Does she like me???help!!!!!!!?

i dunno if she likes me or not but b4 we talked alot and she would say hi to me and once in a while we would fool around then all of the sudden it stopped, i dunno why, she didnt show any signs that i pissed her off, i dont remember doing anything that pissed her off, she said i didnt say anything that pissed her off, so why? once in a while she would smile at me, then there are times where she would just have a blank expression on her face when looking at me and once she frowned when near me? i try to say hi to her but the conversations dont really last long and on fb chat i feel like she doesnt want to talk (possibly cuz she do her hw so i should probably leave her alone? or she say that so she wont talk hafta talk to me?) can someone pls tell me wats going on?