Help trying to understand the mind of a high school boy?

So I'm 17 years old and I'm going to be a senior in the fall (it's summer). I have never had a boyfriend nor was i asked to my prom so i didnt go. I know I'm not ugly and I am nice to everyone so i just dont get why no guys like me. I also see so many other pretty girls at my school who dont have boyfriends and werent asked to prom either. Why is that?