Charting temperature for fertility


Whether you are in the throes of infertility or are trying to conceive your fifth child, knowing exactly how your reproductive system works is essential.

Growing up, we’re all subjected to sex education classes in which we learn that a woman’s cycle is 28 days long and ovulation happens on day 14. That seems to be where the education part stops, and we never truly learn how our bodies work. We’re never taught how to detect ovulation or how and why our bodies change throughout the month. Ever wonder why some days you’re “wetter” than normal down there? Think something’s wrong because you can’t keep your underwear dry?

We’ll tackle that.

Over the next month in the Natural Fertility 101 series we’re going to cover charting for fertility (also known as the Fertility Awareness Method or Natural Family Planning) There are many ways to start charting your fertility signals, the first one being your temperature.

Charting temperature for fertility

Charting for fertility, how to chart your temperature:

At the same time each morning, before you get out of bed (or move or talk), you take your temperature (orally) on a digital thermometer that records your temp within 1/10 of a degree (also known as a basal body thermometer). Chart your temperature each morning on a Basal Body Temperature Chart.

A woman’s temperature sometimes drops just slightly right before ovulation and then rises sharply following ovulation. The rise in temperature should be about .4 degrees. When/if you see this drop, you can know that ovulation will most likely happen soon and if you’re trying to conceive, it’s time to be intimate, if you get my drift. Even if your temperature doesn’t have the initial drop to signal upcoming ovulation, you’ll be able to notice patterns in your cycle that you can combine with other fertility signals to know when you normally ovulate each month. (If you don’t normally see a temperature drop, make sure you’re also tracking cervical fluid)

The unfortunate part about relying only on temperature, is that many times a woman doesn’t notice ovulation until after it’s happened. While it’s always a wonderful thing to know what’s going on with your body, being intimate after ovulation actually makes it more difficult to conceive. If you’re intimate before ovulation, the sperm have a chance to meet the egg when it’s of the best quality.

After ovulation the quality of the egg deteriorates and within 24 hours of being released, it’s no longer able to grow into a new life. In older women or in women with health problems, this window may be even shorter, which is why it’s essential for the sperm to already be there waiting for the egg.

fertility chart with basal thermometer

photo credit: N05

Beyond pin pointing ovulation, charting is also a great way to troubleshoot your cycles. You can find the different phases of your cycle by drawing a line between the follicular phase and the luteal phase. How do you find this? Take a look at the 6 days prior to ovulation (or the decrease in temp, before the increase) and draw a line across the chart 1/10 of a degree higher than your highest temp those days. You should be able to see the follicular temps (1st part if the cycle) are all below the line and the luteal temps (second part of the cycle) are above.

In doing this, you can see how each part of your cycle is acting and whether or not one part is longer or shorter than it should be. One of the most common issues with a woman’s cycle is a luteal defect which can contribute to a fertilized egg not implanting or to early miscarriage. A defect is “diagnosed” as a luteal phase shorter than 12 days, with 12 days being ‘borderline short’. After ovulation your temp should remain above the coverline for at least 12 days. And if it stays above the line (or elevated) for 18 days, it may be an indication of pregnancy.

Also, if you do decide to seek medical counsel after you’ve been unable to achieve pregnancy, these charts can help the doctors (especially NaPro doctors!) find out what may be going wrong and to better diagnose you.

Charting does take time and it does need to be done everyday, but it can also be a very accurate way to achieve pregnancy.

Do you chart? What tips do you have for those just starting?


More articles of interest about charting for fertility:

The basics of your cycle

How to chart your temperature

Charting/checking cervical fluid

Charting/checking cervical changes

Secondary ovulation signs 

Donielle Baker

Donielle Baker

owner and editor of Natural Fertility and Wellness at Natural Fertility and Wellness
I believe women can learn how to heal their bodies & balance their hormones through natural methods. An advocate for natural health, I have a passion for nourishing/real food nutrition and natural living. My personal background includes both infertility and miscarriage and I started Natural Fertility and Wellness in 2008 in order to share all of the information I found helpful in my journey to heal from PCOS and overcome infertility.
Donielle Baker
Donielle Baker
Donielle Baker
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  1. Alison @ Wholesome Goodness

    A lot of people consider my way the lazy one, but I use the LadyComp to do this. It has an alarm that wakes me up at the same time every morning and an attached thermometer that takes my reading down to two decimal points. Then it gives me a light: green if I’m nonfertile, yellow meaning slight possibility of fertility, and red meaning fertile. The red light blinks on ovulation day. I can also look back over my recent cycles, and it will forecast my fertility for the next 6 days. IT tells me what my average rise in temperature is and average cycle length. This has been a life-saver for me! I hesitated over the price as I considered buying it before I got married, but I eventually decided that it was worth it because I was more likely to keep up with charting this way than if I had to do it myself (as Polonius said, “know thyself”). Anyway, we’re using it now for FAM birth control, but we’ll use it in the future for conception. Or, at least, we’ll try. Bad reports coming from the doctor on that. Sometimes I wonder why we even bother to practice birth control… I mean, I know why. If I got pregnant now, it would be bad for baby and me. But then again, that “if” is pretty iffy.

  2. Donielle

    Alison, I have heard of something like that, but never seriously looked into it myself. Good to know it’s easy to use,as we may use some sort of Natural Family Planning in the future! Thanks for the info!

  3. Lindsay

    Love love LOVE the new site!

    I have PCOS too and am just now starting to look into switching our family over to a more traditional foods type approach to nutrition. I’m starting from square one so I really look forward to learning from you!

  4. IJecsMommy

    We used Natural Family Planning for both avoidance of pregnancy, as well as for conception. When we decided we were ready to have baby number 5, we knew my cycle so well, we actually conceived on the first try. 🙂

  5. Spinner

    I started using FAM after reading Toni Weschler’s book Take Charge of your Fertility about six months before we started trying to conceive. I use the software that comes with the book. I find that very handy. I’ve yet to find a basal thermometer that I like. I just tolerate the ones I have because I don’t have another option. I’d love to get a BabyComp but unfortunately I don’t have an extra $700 laying around, lol!

    Tracking my fertility signs clued me into the fact that something wasn’t right early on.

  6. Lizanne

    I’m really keen to try this, because I have PCOS too, and can’t rely on calendar method. My only question is: I just had my son in Dec 2010, and my cycle hasn’t returned, so I have no idea how or when to start – more when than how. I am breastfeeding exclusively, but read that pacifiers can mess with the breastfeeding-as-BC method (LAM). So now I’m a bit confused. Any ideas?

    • donielle

      @Lizanne, Charting while breastfeeding can get pretty tricky – especially since women are so different! I know moms that exclusively breastfeed, no pacifiers, and co-sleep and yet they get their cycles back well before a year. Others work, and baby sleeps on their own and the cycles don’t come back until after baby weans.

      I’d say just start charting now and pay attention to any fertility signs you notice. I’ve also heard that the book “The Art of Natural Family Planning” is a great one for post partum moms!

      • Lizanne

        @donielle, Thanks Donielle! I have “The Art of Natural Family Planning”, I will dig a bit deeper – they seem to focus alot on “ecological” breastfeeding being the best – which is cosleeping, demand feeding and no bottles, pacifiers or expressing. But i’ll start getting a hang of the charting and symptoms so long. My husband wouldn’t mind number 2 soon… but i’m not quite there yet!

        • Jen

          @Lizanne, carries a book specifically about post partum – Very helpful!!! It has guidance whether you are breastfeeding or bottle-feeding, co-sleeping or using a crib, and all in between. It focus on mucus observations as well, and part of it is getting to know your own body. Really helped me through a rocky time, and my cycles fluctuated quite a bit.

          Oh – and diet helps IMMENSELY too – I had bizzare fertility signs for a while that completely went away after improving my diet.

  7. JD

    I have been charting since July and it really does help! I use the website and its sooo helpful. It will mark your ovulation date, predict your menstruation by looking at your information, and a bunch of other neat features.There is a free version, and a paid one that gives you more information. Definitely worth checking out!

  8. Laura @ Homemaking Joyfully

    I have charted off and on for several years and the 2 biggest helps for me have been actually placing my thermometer on top of my alarm clock, so that when I go to turn off the alarm I feel it. And I use the free online charting program at It’s always been accurate for me an takes all the guesswork out of coverlines, plus you have the ability to enter other fertility factors, such as cervical mucus and it takes that into account when calculating your ovulation, etc.

  9. Megyn

    I would love to see some info on charting specifically with PCOS. I’m currently on cycle day 45 charting for the first time, and I feel so frustrated and confused! My temp goes up and down, spiking for a few days to make me hope I actually ovulated, and then plunging back down again. I’ve also had several patches of fertile-quality cervical fluid, but still no ovulation. I can’t find anything anywhere about charting with PCOS…everything assumes that all women have a 28 day cycle with regular ovulation!

    • Stephanie

      I was wondering if you found out any information Megyn? I to would love a chart like that. If I have 2-3 cycles a year I count myself blessed. It’s been really hard trying to keep track of all of the temps and cervical fluids. Even the months that I don’t have a cycle I have all of the cervical fluids…. anyways I was just wondering. Thanks!

  10. Kristina

    I also have PCOS and have charted for 3+ years since marriage. It’s been a life-saver! One thing that really helped me and my husband was taking a class (We actually ended up being trained in both CCLI charting and Creighton charting, and I would recommend either), and having the teachers give a second opinion on my chart. I love seeing when my body is actually ovulating (if it is) and when the fertile patches are just a “fake-out” without ovulation.

    Anyway, I just wanted to comment that all the research I have done states that the “pre-ovulatory dip” is pretty much a myth. If you are waiting for a dip to BD, or to coincide with your temperature rise, don’t hold your breath. While you *might* see one, temperature dips are neither statistically significant nor reliable in interpreting a chart.

  11. Lisa

    I am new to this whole thing. I bought a basal thermoniter & have yet to open the package! haha. Anyway, my question is regarding birth control pills. Our plan is to wait another year or 2, but I thought I’d be smart & start tracking my temps now so I could understand when ovulation normally occurs. But then I thought, I’m taking Ortho-Tri-Cyclen… which is forcing hormones to give me 28 day cycles, which I may not naturally have. I’ve been on the pill for over 10 years & a bit concerned what it’s done. Any suggestions?

    • donielle

      @Lisa, I’m not a fan of BCPs – just thought I’d better throw that one out there so you know what side this is coming from!

      You’re not going to see the same temperature shifts and cervical fluid changes when your on synthetic hormones, because ‘theoretically’ you’re not going to ovulate. Taking your temperature is only going to get you into the habit of doing it.

      Since you’re concerned over what the BCPs may be doing to your system there are a few things you can do to help your body out. eat good nourishing foods, good fats, and very low sugars. Take a B complex vitamin because the pill routinely depletes the system and this can effect fertility. You also want to take good care of your liver as it may have a hard time dealing with synthetic hormones. (

      Personally I think BCPs are very detrimental to the overall health of the woman and don’t recommend them at all. And if it’s something you’re concerned about, I’d recommend learning Natural Family Planning/Fertility Awareness while using barrier methods until you’ve decided to be open to pregnancy. (

      • Lisa

        @donielle, Thanks for the info Donielle, I’m looking into other options, would you say like the cervical cup + spermicide method?

        • donielle

          @Lisa, That,or condoms, would be more along the line of something that won’t affect your hormone balance as you come off the BCPs.

  12. Kendra

    I have been charting for 1 1/2 years. I can’t see to make heads or tails of my temperature. I have had one spike and that was when I had a miscarriage. I have been to the Doctor but he didn’t even want to look at the charts (blew them off completely actually). I live in a small town and not sure where to go from here. My mom suggests progesterone supplements but I am nervous to mess with hormones with out knowing for sure what the issue is. Any suggestions? (I am doing the no sugar and hormone reboot thing)

    • donielle

      @Kendra, I think that for many women that a natural (bio-identical) progesterone can be very helpful. I would really recommend reading the book “What Your Doctor May Nit Tell You About Premenopause” – it’s a really good look at hormone issues and talks all about natural progesterone creams and how to use it. I bought mine at and they have some basic info on it too.

      And yea…..doctors somehow think charts mean nothing {eye roll}. I think they really just have no idea how it all works. lol

  13. Jessica

    My husband and I switched to FAM about 6 months ago (to avoid conception) after I’d been on the Pill for a year. I have always had very short cycles, and now I know why–my luteal phase averages 9-10 days in length. I also have low temps and thought that low thyroid might be an issue (since low thyroid and low progesterone seem to often go together), so I’ve been supplementing with iodine for the last couple cycles. I haven’t seen much change yet (actually, last cycle was the shortest yet!), though my energy levels do seem to be improved. I’m also not 100% sure on the thyroid since Weschler’s book says it’s usually accompanied by long cycles (but I do have heavy menses, so who knows).

    What recommendations do you have for a short luteal phase? I’m having a hard time finding any really helpful information on the web.

    • Sara


      I was able to extend my luteal phase consistently with a good B-Complex which contained a high(ish) dose of B6. I recommend Garden of Life or MegaFood as they are whole food vitamin companies.

      Also, eat foods like tahini (sesame seed) and sunflower seeds during the luteal phase, and supplement with Evening Primrose Oil.

      I went from a 21-day cycle to 27- with this diet & supplementation.

      • donielle

        @Sara, What fantastic results! Thank you for sharing. 🙂

  14. Em

    I would really love to see if you have any info for improving fertility for us of advanced maternal age and with one Fallopian Tube left due to surgery.

  15. Sheila

    I learned the Creighton Model NFP two years before I married. I learned that my luteal phase was only 9-10 days, and my doc supplemented with natural progesterone. He also treated my low thyroid and cortisol levels. He studied under Dr. Thomas Hilgers at the Pope Paul VI Institute in Omaha where the focus is on natural methods to overcome infertility. After six years of infertility (mild endometriosis) I finally conceived and have two babies – 363 days apart. (No problem on round 2, obviously.) I highly recommend anyone concerned enough to be reading here to investigate PPVI Institute. Get off BC pills and learn your body’s cycle. If your doctor rolls his eyes at your charting, find a new doctor. You deserve someone who cares as much as you do.

  16. Jenny

    I have more of a question than a comment. My husband and I have been trying to conceive for about 8 months now. I have been attempting to use the fertility awareness method. I chart my bbt and cervical fluid. I believe I ovulated last Tuesday based on my charting (the spike in the temperature and how everything was looking in the downstairs department, however, since then I have not been dry and my temperature has been steadily decreasing. Since my temperature spike which was about 98.1, I have been charting around 97.6 then 97.5 and this morning at 97.3. This information is confusing to me and I’m not really sure what it means. Please help!

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