Does she like me or not its driving me crazy?

we are both 17 and in highschool. we met around 9 days ago because of a group project and we finished that project now our relationship is getting closer and closer. we hug or cheek kiss whenever we see each other; we both get a huge smile when we look at each other. we text each other alot but sometimes she doest reply but i think she is trying to play hard to get. When she gets on msn we talk until she or i has to go. the thing that throws me off a little is when she doesnt answer texts, is she playing hard to get or is she just not into me?