Fertility awareness (Rhythm)

Effectiveness: 75 to 97 percent; effectiveness increases if you use several methods of tracking fertility, such as calendar, cervical mucus and temperature (24 pregnancies per 100 women each year).

What is it? It's learning to recognize your fertile times by observing and documenting changes in your body as you go through your monthly menstrual cycle. To prevent pregnancy, you avoid having sex during the times you’re most likely to get pregnant, or, if you choose, use withdrawal or a barrier method of contraception during those days. It is also called the “rhythm method” or “natural family planning.” Using a combination of methods to track fertility is known as the symptothermal method.

How does it work? You may use a calendar to chart your menstrual cycle and determine when you are likely to ovulate (release an egg), along with daily documentation of cervical fluid, position and appearance of your cervix (using a speculum and mirror) and your basal body temperature. This information helps you determine the beginning and end of your fertile time.

STD protection: No; you will still need to use condoms if you are concerned about STDs.

Benefits: There are no health risks or side effects and very minimal costs. Most religions are accepting of fertility awareness as a birth control method. It increases your knowledge and awareness of your body and can increase communication with your partner.