I didn't go, though I was asked as a sophomore, and knew of several girls who wanted me to ask them my junior and senior years. I wasn't very social in high school outside of the classroom and running (never went to parties, rarely hung out with anyone on weekends, etc). Also, second semester of my senior year was a really bad time in my life for a lot of reasons and I didn't really care about anything. I almost didn't go to graduation even though I was salutatorian (I didn't have to give a speech or anything, so it wouldn't have really mattered). God, that was a rough time.
I don't regret not going to my proms. I think they're kind of a waste of money. I do regret not being more social though, kind of. A lot of the kids I went to school with weren't really people I wanted to spend time with, but I should have been more open to at least talking to people. No permanent scars though. I have lots of friends now and have been very successful with the ladies in college.
Don't feel bad about not going to prom. It's hugely overrated. It's just one of those things everyone kind of expects you to do, but that doesn't mean it's worth it.