A woman's menstrual cycle usually lasts 28 days, but it varies from person to person. During the menstrual cycle, a woman's ovaries alternately release two eggs, reaching peak viability on the 14th day. On this day, a woman may be ovulating.

However, not every woman will ovulate on day 14 of her menstrual cycle. Some women may take longer to wait for an egg to be released, or may ovulate on day 15 or 16 of their menstrual cycle.

For women trying to get pregnant, it's important to know what ovulation is. If she can accurately predict her ovulation period, she can more easily schedule her sex life to ensure she has a chance of getting pregnant.

The female menstrual cycle and ovulation are very complex and mysterious. Although it is possible to predict a woman's ovulation period by observing indicators such as body temperature, appetite and energy, it is best to obtain accurate predictions with the help of a doctor.