Well if your an introvert that makes it exceptionally difficult to get noticed. Not only do you keep to yourself, you probably don't go out of your way much to get any sort of recognition.
At the higschool level a "Confident" girl would probably have an easier time.
Now I use the word confident loosely here. If you are an introvert, your still young enough to change that. The more you put yourself out there the more confidence you will gain. Just like any muscle in your body, if you work it out enough it gets stronger.
Try and push yourself just a TINY bit more then you did yesterday. it gets easier as you go, just try to avoid becoming over confident. baby steps :)