How to calculate the safe period

The calculation of the safe period is mainly based on a woman's menstrual cycle and ovulation day. The specific calculation method is as follows: 1. Determine the menstrual cycle: You need to know the length of your menstrual cycle, which is the number of days between the first day of one menstrual period and the first day of the next menstrual period. 2. Estimate the ovulation day: Based on the menstrual cycle, you can estimate the date of the next menstrual period, and then count back 14 days to determine the ovulation day. 3. Determine the safe period: The five days before ovulation and the four days after ovulation constitute the fertile window. Avoiding this period as well as the menstrual period, the remaining time is considered the safe period. It should be noted that the safe period method of contraception is not completely reliable, as ovulation may occur earlier or later due to various influencing factors. If contraception is needed, it is recommended to use more reliable contraceptive methods.