I really hope you at least consider what I say here, because it is something that is very important. Defining "crush" as having feelings for a woman, you probably don't have a crush on any girls. To actually love a person is to love them as a person, not as an object for pleasure (aka lovey time). Don't allow yourself to be deluded into thinking that you care about the girl. When you truly do care about her, which is to desire her well being above all your desires, then you'll know.
I have yet to experience that :P
I'm not saying that having a girlfriend at your age isn't okay. It's actually pretty important to try to build relationships. If I hadn't tried, I wouldn't have made any mistakes and wouldn't have learned from those mistakes.