Hi guys, What is the effectiveness of Amoxicillin and yaz. She's been on Amoxicillin since Wednesday, and been on Birth Control for 16 months. My girlfriend got her period on Saturday. We had sex 3 days later, and she started her new pack yesterday which would be monday. We had sex on Tuesday and no i didn't climax in her. I've heard antibiotics reduce the effectiveness of birth control pills. I've also heard since her period just ended the uterus lining isn't formed yet. Shes been on birth control for a while, are we in trouble?

In case you guys were wondering she takes birth control due to her irregularity.