These involve identification of the fertile days of the menstrual cycle. The couple may then avoid intercourse or use a barrier method during those days. The comparative effectiveness of fertility-awareness based methods remains unknown. Proper instruction is critical and complex charting is involved.

Rhythm Method

The rhythm method, also called the calendar method or the calendar rhythm method, is a form of natural family planning. To use the rhythm method, you track your menstrual history to predict when you will ovulate. If you are hoping to avoid pregnancy, you can use the rhythm method to determine which days to avoid unprotected sex.

Using the rhythm method for birth control requires careful record keeping and persistence. If you don’t want to conceive, you and your partner must avoid having sex or use a barrier method of contraception during your fertile days each month.
Using the rhythm method as a form of birth control does not pose any direct risks. However, it is considered one of the least effective forms of birth control. How well the rhythm method works varies between couples. The rhythm method doesn’t protect you from sexually transmitted infections.

Cervical Mucus Method

The cervical mucus method is a type of natural family planning. It is based on careful observation of mucus patterns during your menstrual cycle. Before ovulation, cervical secretions change — creating an environment that helps sperm travel through the cervix, uterus and fallopian tubes to the egg. By recognizing changes in your cervical mucus, you can try to pinpoint when you are likely to ovulate — and when you’re most likely to conceive. If you do not want to conceive, you and your partner must avoid having sex or use a barrier method of contraception during your fertile days each month. Using the cervical mucus method for birth control requires motivation and diligence.

Using the cervical mucus method for birth control does not pose any direct risks, but it does not offer protection from sexually transmitted infections. In addition, the risk of unintended pregnancy with the cervical mucus method is somewhat higher than with other methods of birth control.

Formal training is usually needed to master the cervical mucus method. You will also need to make sure you check cervical secretions every day and keep track of changes. In addition, abstinence — or use of another type of contraception — is typically needed for 14 to 17 days each cycle.

Basal Body Temperature (BBT) Method

The basal body temperature method — a fertility awareness-based method — is a type of natural family planning. Your basal body temperature is your temperature when you are fully at rest. Ovulation may cause a slight increase in basal body temperature.
Two to three days before your temperature rises is when you will be most fertile. By tracking your basal body temperature each day, you may be able to predict when you will ovulate. If you do not want to conceive, you and your partner must avoid having sex or use a barrier method of contraception during your fertile days each month.

Using the basal body temperature method for birth control does not pose any direct risks, but it does not offer protection from STIs. Also, it is one of the least effective natural family planning methods. As many as 1 in 4 women (or maybe even more) who use fertility awareness-based methods to prevent pregnancy will become pregnant after one year of typical use. Because the basal body temperature method alone may not provide enough warning time to effectively prevent pregnancy, people use this method in combination with other fertility awareness-based methods often, to avoid pregnancy.