The Nourished Blog

Why Tracking Your Basal Body Temperature is Important for Fertility Awareness + Health

Along with teaching my clients the importance of tracking cervical mucus, they learn why basal body temperature is an AMAZING clue to their overall health and fertility.

Plus, it’s incredibly empowering when you understand how to interpret your BBT (basal body temperature) chart, and what these temp fluctuations actually mean about your cycle.

You can gain a great baseline of information, before spending a ton of money on hormone tests, just by learning how to read your BBT (and cervical mucus) clues 🤓

Fertility Awareness Method and Basal Body Temperature.jpg

So let’s dive in — shall we?

  1. Helps to confirm ovulation has occurred

This is a big one. I can’t stress enough that your BBT cannot predict ovulation! It can only confirm it.

But confirming ovulation is a sigh of relief 😉 It means that you’re safe to have sex with no worries of pregnancy, or, it means you timed up conception correctly.

After you have ovulated you should see rise in temperature by about .5 degrees.

I want to be clear that not all women see such a drastic temp spike. Some have what is called a “slow rise” where it can be a bit trickier to tell. Some women even have a “fall back rise” where their temp dips before shooting up again.

Everyone’s temps can look different, especially when you’re trying to determine if ovulation has occurred. That’s why it can be helpful to work with a practitioner who can help dig in with you.

But regardless, you eventually will see a pretty significant difference between your pre-ovulatory and post-ovulatory temps which is amazing.

You can also confirm ovulation through your cervical mucus changes — but that’s information for another blog post 😉

2. Gives us clues about healthy thyroid function.

Yep, you heard that right! My clients are surprised to find out that when the have consistently low temps (anywhere below 97.4 … but ESPECIALLY below 97.0) this can be a sign that they are struggling with sluggish thyroid or even subclinical hypothyroid.

When our basal body temps are consistently low, we know that there is metabolic stress on the body in some form. This gives us extra clues when working together as to how we can best support you!

Temps aren’t always the *most* accurate, so we definitely use this data in conjunction with other information: are you consistently cold …especially your nose and feet? Is your hair thin and brittle? Have you had significant weight changes? What does your hair mineral analysis test tell us?

We use ALL this information to formulate a plan that works best for you.

3. Helps determine healthy progesterone levels

I like to see my clients hit at least 98.0 degrees post ovulation. This helps me determine that their progesterone is reaching optimal levels.

Progesterone is naturally heat producing (which is why your temp rises after ovulation). Your body produces the hormone progesterone after your follicle bursts at ovulation. That follicle turns into the corpus luteum and produces progesterone.

In addition to assessing your temperature, we are also able to see how LONG your luteal phase is. If you consistently have high temps for 10-14 days before your next period starts, this is a good sign that your progesterone levels are heading in the right direction.

4. Can predict the start of your period

So cool, right?!

As both estrogen and progesterone drop before your period, so does your BBT. Seeing a decline in temperature gives you an early sign that your period is going to start in the next 24-48hrs.

Get your tampons and menstrual cups ready! 😉

If you’re trying to conceive, seeing dropping temps can be a super bummer. Believe me, I know.

If you’re working closely with a practitioner, you might be able to supplement with progesterone to help keep your levels up, so implantation can occur. There has also been some research that supplementing with progesterone can help prevent early miscarriage.

5. 18+ high temps can indicate a positive pregnancy!

If you’re trying to conceive, what a JOY it is to see that BBT continuing to RISE.

Sometimes, but not always, you will see what is called a triphasic pattern. This is an initial rise in post-ovulatory temps due to progesterone and then a second increase because of all that EXTRA progesterone being released due to implantation (and HGC levels).

I was so pumped when I saw my temp continuing to spike (currently a little over 20 weeks pregnant as I write this post).


Although rare, sometimes continually high temps can mean an unruptured cyst, but this is not common.

A positive pregnancy test is always your best bet (and making that first appointment with your doc!), but your temps can give you a sigh of relief that you’re pregnant!

6. Shows how stress, food, sleep, etc., affects the body

Many of my clients are shocked when they see how sensitive their BBT is to fluctuations in their nutrition and lifestyle.

Did you have some drinks the night before? You may see a significant rise in your temps!

Have you been super stressed recently, or perhaps, you’ve been traveling? You may notice that your BBT is way lower than normal.

Even having to get up and pee a lot in the middle of the night, or experiencing disrupted sleep, can tank your temps.

All this data shows us that our body is so incredibly wise! It becomes very clear what stresses the body out when we see abnormal, our “outlier” temps in our charts.

Now, nothing is wrong with experiencing these shifts from time to time.

We have to live our lives! But, it can be extremely informative when we are building our hormone and fertility protocol together to see what stresses out the body.

So now the question is … how do you start taking your temps?!

You can take your temps aurally every morning with a standard BBT thermometer (I usually recommend @femometer).

Or order a @tempdrop and wear it on your arm overnight and make it SUPER easy!
But remember, if you’re looking to learn fertility awareness method for pregnancy prevention, it is best to work with a trained practitioner.

I am currently taking private clients for FAM + hormone coaching if you’re looking for guidance.

You can schedule a free 30-minute call here OR sign-up for the waitlist for the next group program here.

Always here for you!



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Hi, I’m Nina! I’m a Certified Fertility Awareness Educator who teaches women how to transition off of birth control and prevent pregnancy hormone-free.

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