Last night I had a sexual intercourse with a prostitute. I used a good condom but after 3-4 strokes I felt that the condom wasn't put on properly(I felt discomfort). So I rolled it out and put it on again.There was no direct touch of genital skin. I am concern only because I ROLLED OUT and ROLLED IN the condom. Then I ejaculated after 2-3 minutes. It was my first time and I was very nervous. Didn't know what was happening. Later I thought about it and since then I am scared as ****. I am unable to concentrate. Unable to think. I am very young and don't know much about HIV. Is it possible that if the girl was HIV positive then it might have infected me? What should I do? Please HELP me!