Ovulation is calculated around 1 week before and after the 14th day of the next menstrual period, but due to individual differences, the exact ovulation period needs to be checked with the help of auxiliary tests, such as ovulation test paper. Since women have both regular and irregular menstrual periods, for women who have regular menstrual periods, the ovulation period can be predicted by calculating the menstrual cycle. Normal ovulation is about 1 week before or after the 14th day of the next menstrual period. If the menstrual cycle is 28 days long, ovulation occurs on the 14th day of the cycle. If the menstrual cycle is 32 days, ovulation occurs on the 18th day of the menstrual cycle, and so on to calculate your ovulation. For women with irregular periods, there are other ways to calculate the correct ovulation period, such as ovulation test strips and ultrasound.