About 4 weeks ago I had sex 1 day before my period was due to start. We had some complications with the condoms falling off his penis. So we only went for 10 minutes I'm not sure if he finished or not but I'm sure he didn't in that small amount of time. Three days later I took Plan B I started bleeding I don't remember if it was my period or after my period it freaked me out. Then I had sex again nothing went wrong he finished outside of me with a condom I have never had sex without a condom. But my period is late and I don't feel to good which it could just be stress but I have some weird pains in my hips and lower belly. Is it the plan B what's going on here. I just turned 18 and I'm really scared.