How long until Yaz birth control is effective against pregnancy?
I began taking Yaz birth control a few weeks ago. According to the included pamphlet, it is safe to have unprotected sex 7 days after beginning the pill. I waited 11. Is the pill completely effective after a week for certain, or is there a chance of pregnancy? Thanks A: Most doctors will advise waiting until your second pack to have unprotected sex so that the hormones will be completely in your system.