Why is she acting this way? (Female oppinions) please?

This girl and I have been texting 24/7 almost for a little over two months we hung out at least 4 times and they all went well. By the second month she was being really affectionate towards me, she would call me "boo" and "babe" even "my love" and send me little hearts but lately she stopped showing me that affection her messages are shorter and straight answers. She's been acting very indifferent and I think its safe to say annoyed and everytime I tell her to hang out she makes excuses or says idk if I can. So I say to myself maybe its time to move on so I didn't text her for a complete day, but the day after she texts me saying "You just quit talking to me or what?" What's her deal?