How does a woman count her safe days?

A woman does not count safe days. Safe days are a common misconception about the menstrual cycle. The idea of safe days is based on the belief that there are times during a woman's menstrual cycle when she is less likely to get pregnant. This is not true.

A woman can get pregnant on any day of her menstrual cycle, even during her period. The only way to prevent pregnancy is to use contraception.