safe period

In medicine, that part of the menstrual cycle during which fertilization of the ovum is unlikely to occur.

Ovulation occurs about 15 days before the onset of the menstrual period and a woman is usually fertile for five days before ovulation, on the day of ovulation and for five days afterwards. Therefore, the safe period is the first week and the last ten days of the menstrual cycle. The safe period can be used as a form of contraception, the rhythm method.