What medicines to use to prevent pregnancy

Patient: What medicines to use to prevent pregnancy after having unprotected sex? Its been 3 weeks

Doctor: Hello,Thanks for the query,Unfortunately after 3 weeks post unprotected intercourse, there are no pills available for preventing pregnancy. Emergency contraceptive pills or even IUD have to be placed within 3 days post intercourse. Now wait for the menses to arrive, if they are missed by more than 7 days then get a urine pregnancy test done to rule out the same.Regards