How is the ovulation period calculated

Patient's question:

If my period came on the 12th, what is my ovulation date? What is the best time for conception? Medical history and effectiveness of treatment: I have not received any treatment. What kind of help do I need: To accurately determine my ovulation date

Doctor's answer:

If the menstrual cycle is regular, the ovulation period is 14 days before the next menstrual period. Five days before and four days after this period, plus the ovulation day, the ovulation period will last for 10 days. When a woman's vaginal discharge is like egg white in texture, clear, and highly stretchy, the day before and after the appearance of this mucus can be considered the ovulation day.
The formula for calculating the ovulation period is as follows:
- First day of ovulation period = Shortest menstrual cycle days - 18 days
- Last day of ovulation period = Longest menstrual cycle days - 11 days