I started the DEPO shot in January, and I bleed off and on for what seemed like forever. I finally hit my three month mark and decided to stop depo and start the pill. I started the pill a little over a month ago, stopped bleeding and had a normal period when i was supposed to according to my pill pack. I am now on my second pill pack. I did have an antibiotic that was supposed to mess with it but ended that a couple of weeks ago. We had sex tonight and he ejaculated inside of me. Am I safe or do I need a plan B?