I do not understand girls. Want to give it a shot?

Met this girl at the campus pub a few weeks ago, we traded numbers and had been texting for a while before we met again. Then she invited me over twice in a row, for cider and to watch some halloween horror flicks and we ended up making out and cuddling a bit aftert he last movie when all of her roommates left us alone. I haven't heard much from her since, other than when i initiate the conversation, it IS midterm time, but she is obviously still going out and partying with her friends, so i don;t know what this means. She seemed sweet and said that i was really cute and hot, but now i don't hear much from her even though we are always on facebook at the same time, and she has my cell number. I like her, and i thought she liked me, why would she just cool down like that?