Does taking emergency contraception during the dangerous period cause disorder of menstrual qi?

Patient's question:

No

Doctor's answer:

Hello, emergency contraception pills are only used after an unprotected sexual encounter the previous time and are not effective against the next unprotected encounter. There is a 2% failure rate with emergency contraception pills, and frequent use of Yuting can lead to menstrual irregularities. Frequent use will increase the overall failure rate, so there is a possibility of pregnancy.