A woman identifies when the fertile phase of her cycle begins and ends, avoiding sexual intercourse or using barrier methods during this period. This can be a useful method for couples who do not wish to use another, more effective method of contraception because of religious or other cultural constraints, difficult access to other methods or fear of side-effects. 

Different methods of fertility awareness include using a calendar to predict fertile days, observing changes in body temperature or changes in vaginal discharge.  Fertility awareness allows a woman to learn more about her menstrual physiology, and can be helpful when she does want to become pregnant. 

Fertility awareness methods can also increase pleasure by reducing the fear of pregnancy and by encouraging creativity during fertile periods where abstinence from vaginal intercourse is required. 

However, it requires a great deal of commitment and requires abstinence (or the use of a barrier method) for much of the menstrual cycle. 

Fertility awareness methods are between 75 and 99% effective, but they tend to be less effective for women under the age of 20 because menstrual cycles tend to be less regular, which can make learning and practicing the techniques difficult. 

These methods offer no protection against sexually transmitted infections.