Basal Body Temperature Charting

If you’re new to basal body temperature charting (or BBT thermometer charting), I would like to help you know just how to utilize this powerful tool to determine your most fertile period and also to know if you’re ovulating.

Charting BBT along with other means is a great way to know when and if you are ovulating, and over a period of time you will get to know your cycle better, thus improving your chances of conception.

Your basal body temperature or BBT is your morning waking temperature, or the lowest temperature your body achieves. This is the temperature you take before getting up out of bed, moving around, or eating anything. You can move just enough to get your BBT thermometer, but the less you move about the more accurate your basal temperature reading will be.

Try to check your basal body temperature at around the same time every morning throughout your cycle. If you’re new to charting your BBT ovulation reading, you may need a few months in order to get used to your cycle, especially if you ovulate irregularly.

*An important note: Your BBT will not tell you in advance that you’re getting ready to ovulate. Your BBT will only let you know when you ovulated after the fact. It will also indicate that you did in fact ovulate in any given month. So using basal temperature charting alone is not enough. You need to utilize other methods like checking your cervical mucus and using ovulation predictor kits.

Upon wakening, reach for your thermometer without moving too much (I place mine in the same spot all the time within easy reach). Take your basal temperature while you lie still and doze a bit more. When the beeper beeps, you can take it out and go about your day. Remember to record your temperature with a dot on your chart.

As you utilize BBT ovulation charting throughout your cycle, you will notice some higher temps and some lower temps. Many different factors affect your temperature changes. Some of these are:

  • How much sleep you got the night before compared to normal.
  • Whether you drank alcohol or took medications the night before.
  • Whether you were sick or not.
  • Whether you got too cold or too hot during the night.
  • Whether you took your basal body temperature at the same time as normal or not.

All these factors play a part in the overall picture. So, keep in mind that it’s the overall picture you want to look at.

Also, from menstruation to ovulation, your basal body temperature will be a lower. Then from ovulation to the next menstrual bleeding it will be higher. This is all due to hormonal changes within your body. What you want to look for is a pattern from month to month to help you determine when you normally ovulate.

As you are charting BBT, after ovulation you will notice a spike in temperature from about 0.5 degrees to about 1.6 degrees. You are most fertile from about two to three days before ovulation until about 12 hours after ovulation. So once your temperature has spiked, chances are it’s too late to make a difference for that month (although it can’t hurt to try!).

Order a Digital Basal Thermometer here.

Free printable BBT Chart

Learn More About Determining Ovulation here.