The starting date of ovulation refers to the number of days in a woman's menstrual cycle minus 18 days, and the resulting number of days is the starting date of ovulation. For many women, figuring out when they are ovulating is a very important process because it can help them better predict whether they will become pregnant.

However, these methods are not completely accurate because women's medical conditions may affect their cycles and fertility. Therefore, calculating ovulation is very important for those who want to better predict whether they will become pregnant.

To calculate ovulation, a woman needs to know the number of days in her menstrual cycle and follow these steps:

1. Record the number of days in your menstrual cycle.

2. Subtract 18 days from the number of days in the menstrual cycle, and the resulting number of days is the starting date of ovulation.

3. Follow this method and take the test on the same day each month to determine if you are pregnant.

Calculating ovulation is not an easy task, but it is very important for those who want to better predict whether they will become pregnant. If women encounter difficulties during their menstrual cycle, they can consult a doctor or professional consultant for better help.