How to Calculate the Safe Period of the Menstrual Cycle

Generally, the safe period of a menstrual cycle can be calculated using the calendar method. This method is based on the regularity of the female menstrual cycle and determines the ovulation day and safe period by estimating the date of the next menstrual period. The specific analysis is as follows:

First, it is necessary to determine the length of the 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. Generally, the ovulation day occurs about 14 days before the next menstrual period begins. The five days before the ovulation day and the four days after, including the ovulation day itself, constitute a 10-day period known as the ovulation period, during which pregnancy is more likely. Excluding the menstruation period and the ovulation period, the remaining time is considered the safe period, when pregnancy is less likely. However, it is important to note that the safe period is not absolutely safe, as a woman's ovulation can be influenced by various factors and may change, such as due to emotional fluctuations, environmental changes, etc.

It is recommended that women record their menstrual cycles to more accurately estimate the safe period and ovulation period. This helps identify the regularity and changes in the menstrual cycle, thereby improving the accuracy of safe period calculations.