Level 1: What is the safety period? The safe period refers to the 5 days before ovulation and 4 days after ovulation in a woman’s menstrual cycle. During this period, women are not likely to get pregnant. This is because a woman’s egg can only be fertilized within 24 hours after ovulation, while sperm can survive in the body for 3-5 days. Therefore, having sex 5 days before ovulation and 4 days after ovulation will almost never lead to pregnancy. . Level 2: Safe Period Calculation Method To calculate the safe period, you need to know the woman’s menstrual cycle. The menstrual cycle is from the first day of one menstrual period to the first day of the next menstrual period