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Basal Body Temperature: All Your Questions Answered Part I

Basal body temperature is one key piece in charting your fertility signs with the fertility awareness method, which is essential for avoiding pregnancy, getting pregnant or tracking your health. We asked our users what their burning basal body temperature questions were, and we answered! 

(Psst: This is the first part in a series about basal body temperature. Don't forget to sign up for our newsletter to stay in the know on our latest blog posts, news, and promotions!)

When Is The Best Time to Take My Basal Body Temperature?

Your basal body temperature is your body’s lowest temperature attained during rest. Basal body temperature rises in the second half of the cycle, after ovulation, due to the presence of the hormone progesterone. The best time to take your temperature with an oral basal body thermometer is after three hours of consecutive sleep, before you get out of bed to go to the bathroom, cuddle your partner, take a drink of water, or fall back asleep. With Tempdrop, you can keep your armband on while you get up to go to the bathroom or tend to your baby and it will not disturb your temperatures, and it isn’t necessary to temp at the same time every day. 

What Is Rounding? And Does It Matter That Much?

I would say that yes, rounding does matter! Rounding makes your chart easier to read, and takes the guesswork out of a temperature shift that may be iffy or hard to determine. What rounding does is it keeps everything on the same lines in your chart. Rounding in Celsius is rounding to the nearest .05 or .00. For Fahrenheit, some people do the same and scientifically round to the nearest .05 or .00, but because the difference between degrees in Fahrenheit is different, you can also just drop the last digit. 

Celsius (scientific)

Fahrenheit (scientific)

Fahrenheit (dropped digit)

36.31

36.30

97.91

97.90

97.91

97.90

36.32

36.30

97.92

97.90

97.92

97.90

36.33

36.35

97.93

97.95

97.93

97.90

36.34

36.35

97.94

97.95

97.94

97.90

36.35

36.35

97.95

97.95

97.95

97.90

36.36

36.35

97.96

97.95

97.96

97.90

36.37

36.35

97.97

97.95

97.97

97.90

36.38

36.40

97.98

98.00

97.98

97.90

36.39

36.40

97.99

98.00

97.99

97.90

Is It Really Essential to Try and Pinpoint the Exact Ovulation Point? I Can’t See a Clear Thermal Shift From One Half of My Cycle to The Other. The Exact Peak Temp Is Difficult to Spot. 

If you are having a hard time seeing a clear thermal shift, that’s okay! It sometimes takes a bit of practice to have the “eyes” to see a clear shift. Ensuring you round your temps will take some of the guesswork out if it. You want to look for a higher range of higher temperatures, and more specifically for your shift, one higher temperature that is higher than the previous 6 days. This high temperature should stay above your coverline, that is the line that indicates the difference between your low pre ovulatory temperatures and higher postovulatory temperatures. 

basal body temperature temps from Tempdrop

My Biggest Question Is Why Don’t Many Physicians Believe in BBT Charting?! I’ve Had to Search for Someone Who Actually Took It Seriously!

You know, I wish I knew the answer to this myself! Many doctors don’t take fertility awareness methods of birth control seriously, and by extension, may not take charting your basal body temperature seriously. Good on you for searching for someone who supports your decision to chart your cycles, because you don’t want to waste your time convincing someone of something that you know for yourself, and thousands of other women, works. Basal body temperature is a wonderful objective measure of ovulation, and for that reason it is easy to show that you have ovulated. 

What Does It Mean if My Basal Body Temperature Dips During My LP?

One of the most common reasons for a basal body temperature dip in the luteal phase is due to a surge of estrogen. Estrogen is a hormone that is dominant during the follicular (pre ovulatory) phase of the cycle. Progesterone is dominant during the luteal (post ovulatory) phase of the cycle. This is not to say that estrogen isn’t hanging around during the luteal phase. Sometimes it can rise a little bit during the luteal phase, especially right after ovulation, causing your temperature to dip. 

Can Room Temp And Pajamas Worn at Night Affect BBT?

With oral basal body thermometers, room temperature can definitely raise or lower basal body temperature. Make a note in your chart if you suspect that something like room temperature will affect your basal body temperature. If you are wearing pajamas that make you feel significantly warmer or colder than your normal, then it could theoretically affect your basal body temperature. 

With Tempdrop it is recommended that if you are sleeping somewhere significantly colder than normal (like going camping) you should wear a long sleeved shirt while you sleep. This will mitigate any outside influence and keep your temperatures as stable as possible. Room temperature will not influence Tempdrop temperatures as it is designed to exclude any outside interference with things like room temperature or getting up in the middle of the night to go to the bathroom.  

Nathalie Daudet, Social Worker and FEMM InstructorNathalie Daudet is a social worker and FEMM instructor based in the centre of Winnipeg, Canada. She discovered fertility awareness after searching high and low for a non-hormonal method of birth control. After learning the magic of fertility awareness and the gift of body literacy, she decided to pursue formal fertility awareness training and share the knowledge of fertility awareness with women looking for a natural birth control option. Fertility Awareness Project is the hub for Nathalie’s FEMM classes in both group and individual formats, online and in person in Winnipeg, Manitoba. She can be reached at fertilityawarenessproject.ca. If you love this post and would like to thank Nathalie, shop Tempdrop with Nathalie's unique referral link

1 comment

Sep 11, 2019 • Posted by Janice Green

Excellent post, Nathalie! I love my temp drop!

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