Hi. I am eighteen years old and a virgin. Recently, my boyfriend and I got close to having sex. We were just messing around, so we didn't think much of it...but we slowly moved to almost having sex. But, we did not use a condom. His penis went in my vagina, but not fully. It was probably less than 10 seconds long that he was in when I decided I did not want anything more to happen. I am on a birth control pill, but I was on antibiotics at the time so now I'm worried that I could be pregnant..