ask her. don't just assume that her vagina will reveal her recent sexual past while you were not together. did you have some sort of an understanding that she would not date or have sex with others while you were absent? were you celibate for the last three months? if either one of you have had unprotected sex it is std screening that should be your major concern.
three month we were having sex but her vagina is too loose as same as before? is she having sex with oters guys?