How to Correctly Calculate Women\’s Ovulation Period Women\’s ovulation period refers to the time when a woman\’s egg is released from the ovary. During the ovulation period, a woman has the highest possibility of becoming pregnant. Correctly calculating a woman\’s ovulation period can greatly increase the chance of pregnancy. The following explains how to correctly calculate a woman\’s ovulation period from four aspects. Understanding your cycle A woman\’s menstrual cycle begins on the first day of her last menstrual period and ends on the first day of her next menstrual period. The average cycle is 28 days long, but not all women are 28 days long. Some women have short cycles and some women have long cycles.