How to accurately calculate the ovulation day?

Patient's question:

As a girl, I feel very troubled because girls have menstruation. However, my menstrual period is not very regular; it always comes a day or two earlier or later. This makes it impossible for me to prepare in advance for Aunt Flo's arrival, and I have suffered a lot as a result. What kind of help do I need: How can I accurately calculate the day of ovulation?

Doctor's answer:

Method of Calculating Female Ovulation Period
Hello, if your menstrual cycle is regular, you can predict the date of your next period based on the regularity of your cycle. Then, 14 days before your next period is your ovulation day.