Ovulation calculators are a common method that can help women predict the best time to have a baby. Women can better plan their lives by using an ovulation calculator to determine the best time to get pregnant.

Here are some commonly used calculation methods:

1. Calculation method of cycle days: Add 14 days to the number of days in a woman’s cycle, which is the woman’s pregnancy time. For example, if a woman's cycle is 28 days, her pregnancy would be 28 days plus 14 days, or 52 days.

2. Cycle days minus 14 days: If a woman’s cycle is 28 days, then her pregnancy time should be 28 days minus 14 days, that is, 14 days.

3. Calculation method for the date of last menstrual period: Add 14 days to the date of a woman’s last menstrual period, which is the woman’s pregnancy time. For example, if a woman's last menstrual period was February 10th, her pregnancy would be February 10th plus 14 days, which is February 14th.

The above methods are just some commonly used calculation methods. Women can also use other methods to determine the best time to get pregnant. For example, women can determine their best pregnancy time by measuring their body temperature, observing their symptoms, observing body changes, etc.

Women can better plan their lives by using an ovulation calculator to determine the best time to get pregnant. Women should use caution and follow the guidance of professionals when using these methods. If a woman is not sure how to calculate her pregnancy time, she can seek advice from her doctor or professional.