My girlfriend isn't being a girlfriend...?

Okay well my gf is not being true to me? Or at least I don't think so we are teens and we go to different high skools and we see each other on the weekends but she is inexperinced girlfriend for I am her first boy tht her mom no she's with(one other boy she was with she was with secretly) now don't get me wrong I'm not tooting my own horn but this girl is very attractive and very nice and sometimes not assertive enough but she is with me but is hit own by other guys and acts as if she doesn't have a boy friend she turns them down and still claims them as a friend but she turns them down but in a way as if she's playing hard to get she tells me about these situations but it get to me cuz if the shoe was on the other foot I'd make sure tht thing Wer clear enough for the girls to no I'm not interested it's almost as if she like the attention I've told her u no just let them no u lik someone else already.. Just recently she told me of her plans about one of her "friends"house she wanted to go over and watch some movies and I'm suspicious about this.. I mean I obvious I trust her but I just not in the right state of mind about it.... I don't think shed do me dirty cuz I was her "first" and I'm not tlking bout first bf... But this really puzzles me what should be my next set of actions I lik this girl and want it to work am I just paranoid??... Any help is appreciated ONE LOVE!