A woman's menstrual cycle usually lasts 28 days per month, but there are many factors that can affect a woman's cycle, such as disease, medications, and living environment. For many women, figuring out when they are ovulating is important because it helps them plan a pregnancy or other fertility-related activities.

In addition to calculating ovulation, there are other ways to help women plan for pregnancy. For example, women can predict ovulation by measuring basal body temperature and observing secretions. Women can also start using a pregnancy test stick on the 10th day of the menstrual cycle or go to the hospital for a test to determine whether they are pregnant.

To sum up, calculating a woman’s ovulation period is very important and can help women plan pregnancy or other fertility-related activities. If you have a 16-day menstrual cycle and your last period was April 16, your ovulation should be around May 3. If you need more information or help, please talk to your doctor or professional fertility counselor.