I don't understand this girl?

So I had my first kiss with this girl, but I never told her that I hadn't had my first kiss up until that night. She texted me the next day an told me she felt used. I asked her if she would've kissed me if I told her I had never had a first kiss, she never responded. I told her it was not my intention to hang out with her solely to have my first kiss, so she said we could still be friends, but I could tell she was angry.

That was 4 months ago. Today she still acts the same around me as before, but anytime I'm online on facebook, she tries to start a chat up with me. And at school she's always making weird sexually references which she's never really done before. I'm confused by her. I still have feeling for her, but I don't know if she's trying to tell me something. Can anyone help?