WOMEN! I don't get em! Do you?

This girl says she loves me and has for many years..I am sure I take advantage of it but its hard not too when you know they will always be there. My birthday is in a few months and up until this point she has been asking what I was doing for it, and if she could come..I just told her I don't know whats going on and its in someone else's hand..I am turning the big 30 and she really wanted to be a part of it but I kind of liked her being antsy about it all.So I never said I wanted her to go..I just said I don't know what all is going to happen... So she stopped talking to me for awhile( she always does this!) and so I called her last night and asked if she was going to come see me next month for my bd and she told me she was going to let me do my own thing on my birthday... I don't get it..why does she all of a sudden not want to come?