I am 18. I recently and foolishly lost my virginity to a girl I had met for one night. I put on a condom but throughout the course of intercourse the condom slipped off. We did not have sex for very long at all. There was no forceful sex and I didn't even remain hard for most of the encounter. I checked my penis for any tears or sores but didn't find any. I am terribly afraid. I would never not use a condom please tell me if my worries need be considered. Thank You

The likelihood of a man without lesions on his penis becoming infected after a single encounter with a woman are extremely low. I won't say it can't happen, but I don't think you should loose sleep over it. In this part of the world, a woman is in much more danger of becoming infected by a man than vice versa, and from what you say, it doesn't sound like you put HER in any danger.

If you keep worrying about it, then get tested in 3 months. But I would say that you are at very low risk.