
One of the biggest roadblocks with learning Fertility Awareness Method seems to be building the habit of taking your morning basal body temperature on a daily basis.
Basal body temperature is your temperature when you’re fully at rest.
For an accurate reading, you need to wake up around the same time every day (within 30-mins) and take your temperature as soon as you wake up. This is because your temperature rises by .1 degree about every half hour.
No getting out of bed, no going to the bathroom first, and ideally after 3 hours of consecutive sleep.
So what does tracking your basal body temperature (BBT) actually tell you in regards to your fertility?
One huge mistake I see when it comes to tracking BBT is the thought that your temperature helps you predict when ovulation is approaching.
This is NOT true (even the Mayo Clinic has this information wrong on their site!).
BBT does not predict ovulation – it can only CONFIRM when ovulation has already passed.
This means that tracking your temperature for natural birth control is a highly effective cross-check to determine when the fertile window has closed.
While there technically is a “range” of days when temps can rise, BBT most often rises 2-5 days AFTER ovulation has passed.
This is because once the egg has been released from the follicle, that follicle turns into what is called the corpus luteum.
The corpus luteum produces progesterone for the remainder of the cycle, and because progesterone is heat producing, you will see a rise in temperature post-ovulation.
Basal body temperature helps you to see a beautiful bi-phasic (2-phase) pattern between your follicular and luteal phases – aka- your pre-ovulatory and post-ovulatory phases.
See example below!

You may be wondering… “Ok, then how in the world do I predict when ovulation is approaching so I can avoid getting pregnant?”
This is where the power of cervical mucus comes in! I talk all about that in this blog post.
Some women can very quickly fall into the habit of taking their temps every morning.
Just keep your thermometer next to your nightstand, set your alarm for the same time every day, take your temp, and log it in your charting app.
This takes about 2-3 minutes out of your morning. You can even do it with your eyes still closed!
For others, this habit can be TRICKY.
Especially if you work an inconsistent schedule, have trouble sleeping, or maybe … you’re just forgetful! 🤪
In this case, you have options!
So, let’s talk about thermometers and what options might be best for you:
Oral Basal Body Thermometers
The only specific thing you need to look out for is that your thermometer is tracking to the 100th degree (ex: 97.79 not 97.7).
The standard thermometer you might use when you’re sick will NOT track to the 100th degree.
While you can purchase a BBT thermometer at your local pharmacy or drugstore, here are a few other devices I recommend:
For those of you that struggle with consistent wake times or inconsistent sleep schedules, then I recommend using Tempdrop.
Tempdrop is a wearable thermometer that you put on right before bed.
Tempdrop’s smart algorithm learns your unique nightly and monthly patterns to filter variables that can otherwise skew temp results.
It also offers continuous monitoring, filtering out waking times to give you a true nightly sleeping temperature.
Highly recommend it.
You can use my code: NINA12 to get 12% off your device.
So, while BBT doesn’t help you prevent pregnancy PRIOR to ovulation happening, it allows you to confirm when ovulation has passed, opening up an entire second half of your cycle where you are safe for unproected sex!
In my online fertility awareness method classes, I teach researched protocols for using basal body temperature and cervical mucus to identify your fertile and infertile phases of the cycle.
Giving you 99% accuracy for natural birth control using the fertility awareness method!
I also have a FREE 90-minute fertility awareness method training that will help you gain the confidence to ditch birth control and prevent pregnancy naturally.
Happy temperature tracking, FAM!
