Waiting for the break up, what to do?

ive been seeing changes in my girlfriend as of late. I don't know if shes scared or tired of me, but every time i ask "are we fine", she says yes. im confused because we usually have good communication, but she seems distant. Only thing i know is she doesn't answer my tex but for others she does and i don't even tex that much 1 a day....help some one ?