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Trying to get pregnant? Don't worry if it doesn't happen quickly -- you may just need to work on your timing.

As you go through your menstrual cycle, your body gives you clues about when you're ovulating. By charting your cycle, you'll know when you have the best chance to conceive. 

Why Chart Your Menstrual Cycle?

Charting can help you:

  • Become pregnant more quickly.
  • Create a record of your cycles that you can share with a fertility doctor, if needed.

Taking Your Basal Body Temperature

Your basal body temperature (BBT) changes throughout the month according to where you are in your cycle. Tracking your BBT helps you determine when you're most fertile.

  • Before ovulation, your BBT is usually about 96 F to 98 F.
  • During ovulation, your body releases the hormone progesterone. This raises your BBT by 0.4 to 0.8 degrees a day or two after ovulation.
  • This rise in temperature usually lasts until your period starts.
  • If you become pregnant, your temperature will stay elevated during your pregnancy. After charting for a couple of months, you may see a pattern emerge.
  • You're most fertile two to three days before ovulation, and 12 to 24 hours after ovulating.
  • Sperm can live up to six days in a woman's body. So your best chance for conception is to have sex a few days before you ovulate.

BBT charting is widely used, but it's not foolproof.

  • Some women may not see a clear pattern.
  • You may ovulate at different times in your cycle from one month to the next. This can make it hard to predict.

Tips for Taking Your Basal Body Temperature

  • You'll need a basal body thermometer. You can find them at most pharmacies. A regular one can't detect such a small change in temperature.
  • Keep the thermometer, paper, and pencil by your bedside.
  • Take your temperature the same time every morning while still in bed.
  • Don't do anything before your measuring your BBT. Don't eat, drink, smoke, get up, or move around.
  • You can take your temperature orally, rectally, or vaginally. Do it the same way every time.
  • Make your own graph, or find one online. There are also iPhone and Android phone apps available.
  • Your doctor can help you interpret your chart.