I have female problems?

I have been hanging out with this girl for a few weeks. We haven't kissed or anything, but we have held hands and snuggled a few times. I interpreted this as her liking me. This last Friday she invited me over to hang out. We got comfortable and close and I sort of just kissed her. She kissed back for a few seconds, then she said "This is dumb" and just kind of blew me off. I then told her I liked her, too which she told me she had no idea. She also implied that she didn't feel the same way about me. I would have expected her to ask me to leave, but nothing really happened and we kept snuggling like nothing happened. This week, she has been completely ignoring me at school. What does this mean? I have already made it obvious that I like her, but she is giving me mixed signals. What should I do?