The rhythm method of birth control, also known as natural family planning, fertility awareness, or periodic abstinence, involves tracking a woman's menstrual cycle to determine when she is most fertile. This method requires abstaining from intercourse during the woman's fertile period to prevent pregnancy. There are several other methods of natural family planning, including the sympto-thermal method, cervical mucus method, and basal body temperature method. These methods all involve tracking changes in a woman's body to determine when she is ovulating and most likely to conceive. While natural family planning can be effective for some couples, it is not as reliable as other forms of contraception such as condoms or hormonal birth control.