Bleeding two weeks after sex

TMI! Hello! So, about 2 weeks ago I had sex(I am on the birth control pill and have been since I was 14 I am 17 now) last time I had sex was 2 years ago. Okay so It was unprotected and kinda rough, during sex I began bleeding a lot. I had finished my period a week before we had sex. I continued to bleed for about 4 days but it was light. It's been two weeks and today I saw a small amount of clear looking blood. I also have had a little pelvic pain. What could that mean ? Thank you to anyone who may know