The calendar method of birth control focuses on tracking a woman's natural menstrual cycle to predict ovulation, according to Planned Parenthood. It is a natural method of both preventing pregnancy as well as planning for conception.
Significance
Unlike other methods of birth control, the calendar method does not require any tools or chemicals to be effective. According to the Mayo Clinic 13 out of every 100 women practicing this form of contraception will become pregnant.
Tracking the Cycle
To begin the calendar method of birth control, a woman must mark the first day of each menstrual cycle on a calendar. This first day is signified by the shedding of the uterine lining when most women experience bleeding.
Predicting Ovulation
According to Planned Parenthood, ovulation can be predicted after eight cycles. The calculation consists of counting the number of days in each cycle, identifying the shortest and the longest cycles, and then computing the first and last fertile day in the cycle.
Avoid Unprotected Intercourse
Based on the calendar method a woman should avoid intercourse or use a back up method of birth control between the first and last day of predicted fertility. This is also the best time to have unprotected sex when trying to conceive a child, per Planned Parenthood.
Risks
The calendar method of birth control does not protect against sexually transmitted diseases. It is also not as effective for women with cycles shorter than 27 days, per Planned Parenthood.
