How do I use basal body temperature and cervical mucus to predict ovulation?

If you're trying to get pregnant, it's helpful to know exactly when you ovulate so you can time sex accordingly. Many women have had success using ovulation predictor kits, which are handy because they tip you off before you ovulate. Others prefer to track their ovulation cycle by charting their basal body temperature (BBT) and monitoring their cervical mucus (CM).

What is basal body temperature ?

Your basal body temperature (BBT) is your lowest body temperature in a 24-hour period. To get an accurate reading, you must take your temperature when you first wake up in the morning, before you even sit up in bed. And you'll need to use a basal thermometer, which is sensitive enough to measure minute changes in body temperature. Try to wake up and take a reading at about the same time each morning.

Before ovulation, your BBT probably ranges from 97.2 to about 97.7 degrees Fahrenheit. But two or three days after you ovulate, hormonal changes cause a rise of 0.4 to 1.0 degree in your BBT, which lasts at least until your next period. If you become pregnant, your temperature will stay elevated throughout your pregnancy.

What is cervical mucus?

There are many different types of vaginal discharge, one of which is cervical mucus. Over the course of your menstrual cycle, the amount, color, and texture of your cervical mucus will change, thanks to fluctuating hormone levels. Checking your cervical mucus and keeping track of these changes can help you figure out when you're ovulating.

Beginning with your period, you'll, of course, have menstrual blood. When your period is over, you'll most likely be dry for several days. After that, you'll start to have cloudy mucus that's roughly the consistency of sticky rice. You're not very likely to conceive on any of these days.

A few days before ovulation, the mucus will become clear and slippery, very much like raw egg white, and you'll have more of it. This type of mucus means it's baby-making time as its clear, slippery quality makes it easier for the sperm to travel to the egg. The last day you see this egg-white consistency is the day that you're most fertile - usually the day before ovulation or the day of ovulation.

A good time to check your cervical mucus is when you first go to the bathroom in the morning.

Charting your basal body temperature and cervical mucus can help you look back on your cycle and see when ovulation happened.

Your most fertile period is during the three days leading up to ovulation. You can start a little earlier, too, if you want - some women have gotten pregnant from sex that happened six days before they ovulated.

You're fertile during this whole stretch because sperm can survive for five or six days in your body, and your ovum (the egg released at ovulation) can survive for one day. Most experts recommend having sex every day or every other day during your fertile period for the best chance of conceiving.