Whether or not you are working on becoming pregnant, tracking your fertility cycle can help you plan ahead for conceiving or not conceiving. Monitoring fertility with basal body temperature is among the easiest, least expensive, and most reliable methods.

What is Basal Body Temperature?

Basal Body Temperature (BBT) is your body’s lowest temperature in a 24-hour period. Before ovulation, your BBT may range from about 97 to 97.5ºF .

During ovulation, your body releases the hormone progesterone, which triggers a rise in temperature. The day after ovulation, you should see a slight increase in temperature, normally about 0.5 to 1º.  This increased temp should last until the start of your next cycle. Note that the temperature increase always happens after ovulation. This means that once you see that rise, you’ve likely already missed your chance to become pregnant in that cycle. But a few months of charting your temperature will reveal your body’s patterns and help you predict when you will be most fertile. Once you do, you can use this information to decide when its go time.

How It’s Done

You need to purchase a basal body thermometer. Regular thermometers aren’t sensitive enough to measure the minute changes you are looking for.

Begin taking your temperature first thing in the morning, before getting out of bed. Make sure you do this before eating, drinking, brushing your teeth, etc. It will be most accurate before your feet even touch the floor. It’s also best if you remember to take your temperature at the same time every day.

Record your temperature each day. You can make a fertility chart or just a simple listing of your BBT each day. Look for those small increases in temperature to determine ovulation. You may have an occasional high reading that doesn’t fit into the pattern. Just ignore those readings and look for the overall picture.

Now What?

Whether or not you are wanting to conceive, you can use this information to plan the best times for intercourse. If you do want to get pregnant your ideal time would be the few days just before the sharp increase in temperature. If you are using the BBT method as contraception, those are the days during which you would want to avoid having sex.


Using the BBT method as contraception? Want more natural contraception methods? Check out this blog post!

Looking for education about essential oils, supplements, and wellness? Check out my book, Essentials: 75 Answers to Common Questions About Essential Oils and Supplements! Or come check out this class on reproductive hormone health.