Do you think this girl likes me?

We've been close for more or less 3 months now, since we got into college. We had common friends in high school and we're taking the same degree so when we got into college we started to go there together and we hang out almost all the time. We text to each other almost everyday we aren't together and she is always asking me to help her studying even though I'm not any better with the books than her, and she knows it. She invites me to her home every now and then and also tells me lots of secrets.

I really, really like her but I'm afraid to do something without being sure if she feels the same.

In case you think I can't be sure, should I ask her out anyway, to go watch a movie or something?

Please help me.