Ovulation period calculation formula

　　The formula for calculating ovulation period is:

　　The first day of ovulation = the number of days in the shortest menstrual cycle minus 18 days

　　Last day of ovulation = longest menstrual cycle minus 11 days

　　Before using this formula to calculate, I am required to observe and record my menstrual cycle for 8 consecutive times, and get the longest and shortest days of my menstrual cycle. The numbers obtained by substituting into the above formula represent the start and end of the woman's "ovulation period" respectively.

　　(The menstrual cycle is calculated from the first day of this menstrual period to the first day of the next menstrual period.) For example: the longest menstrual cycle of a woman of childbearing age in the first 8 months is 30 days, and the shortest is 28 days. The substitution formula is:

　　The first day of ovulation = 28 days - 18 days = 10 days

　　The last day of ovulation = 30 days - 11 days = 19 days

　　That is: this woman's "ovulation period" begins on the 10th day of her menstrual period and ends on the 19th day of her menstrual period.

　　If through observation, your menstruation is very regular: once every 28 days, then you can set the longest and shortest days of the menstrual cycle as 28 days. Substitute into the formula to calculate your "ovulation period" as: the 10th to 17th day of this menstrual period. This calculation method is based on the first day of the current menstrual period and counts the days backwards, instead of using the next menstrual period as the base point and counting the days backwards, so it is not easy to make mistakes. After finding out the "ovulation period", if you want to get pregnant, you can start from the first day of the "ovulation period" and have sexual intercourse every other day for several months, and you are very likely to get pregnant. If you don't want to get pregnant, you have to miss the "ovulation period" and have sex.