I'm 18 and have been in a relationship for the past 11 months. About a month ago I finally decided to try anal with my partner as I'm too worried about having vaginal sex and becoming pregnant add I'm not on any birth control, however it was unprotected. The first time we did it was when I was on my period (I wear tampons) and the second time was probably about a week to 10 days after. Those were the only two times we had anal. But lately I've had my period every 28 days, but this time it's late. It hasn't been late for months, but I am now at 4 days late. I'm scared that some of his sperm leaked down to my vaginal opening and that I could be pregnant. Do you think I am? Am I just over worrying about it?