I've known this girl for a few years now and and been really good friends with her. I know she liked me because when she was going out with her bf she said she did. We did make out a few times when she was going out, but I know she felt bad about it (this is like a year ago). Recently we started seeing each other more and would hookup more often and what not. She wanted to have sex, but I did not want to and she knew I didn't want to before saying it. After we have been hooking up more, I feel like she is just losing interest or playing hard to get. I would try to make plans to chill with her, but she often comes up with an excuse. It kind of pissed me off so when she asked me to hang out I said I was busy with something else. A few days later we made plans to chill last night so we could watch a movie and she was going to sleep over, but at night she gave an excuse about her roomies being with her so she couldn't and that she wanted to go to bed soon. Pretty much the same excuse she has been using for a while now.
I'm not really sure where I went wrong, but things haven't been the same between us. Txting wise, she would usually reply within an hour of any txt, even if I were to reply to hers hours after or even a day after. Now she will always take a few hours even the whole day to respond back. She does however respond to my txts from the previous night really early in the am when she wakes up.
In our most recent txt exchanges I had something of hers so I said:
Me: If you want it you have to come get it :p
Her: Haha I don't need it right now
Me: I never said to come right now (sent it pretty early at night)
Her: Okay goood

(she sent that early in the am)
I'm not really sure on how to handle this as I have never quite been in this situation before. Any tips?
I was thinking I can just leave it at that and ignore her for a few days and see where it goes or I will talk to her and try to straighten out w.e is going on between us. Thanks