How often does the menstrual cycle come after taking birth control pills?

Patient's question:

Taking emergency contraception for a month, menstrual disorders, how often do they come

Doctor's answer:

After taking emergency contraceptive pills, if withdrawal bleeding occurs again 3~7 days later, it may easily disrupt your menstrual cycle. The next menstrual period is usually estimated based on the date of this bleeding. If your period hasn't arrived within a week, you should take a pregnancy test to rule out pregnancy. If it's not pregnancy, you can take progesterone to induce menstruation. It's recommended to develop good living habits and exercise moderately to strengthen your body. If you're overweight, you should adjust your diet appropriately, as excessive obesity can interfere with ovarian function. If you're not planning to get pregnant, you should use other measures. Emergency contraceptive pills should not be taken casually, as they can easily disrupt your menstrual cycle. They are only suitable as a backup measure after other contraceptive methods have failed and should not be used as a regular form of birth control.