I thought she was interested in me. But i guess not? I'm confused.?

Sounds like you have been pussyfooting around for a loooong time-shes probably sick of waiting for you to approach her and ask her out?If youre interested in her,just go tell her!Ask her out for a coffee or lunch-or something.She will either say yes or no.That will give you a good indication about whether or not shes interested in you.