UTI after sex

Okay so my boyfriend is an hour away at college and I only see him on weekends when I get the chance to drive out there. We tend to have a LOT of sex when we're together to make up for the time we haven't been together lol. Problem is almost every time after sex I'll wake up the next morning with a terribly painful UTI. I go pee before and after sex almost every time to try to avoid it and I'll try to clean up down there too but it's almost to the point where I just expect to get one. Does anyone else have this problem?? Are there any other ways to avoid it?