My girlfriend has been on the depo shot for a year this last shot being her fourth shot she has always been on time and never missed a shot she is rather young her mother makes sure she doesn't miss one but she got her last shot December 22nd we had unprotected sex the 25th then again on January 10th more then twice while we were talking she said her breast have been sore and she has had a crazy sex drive lately that's all she has wanted to do she asked her doctor if she could get pregnant on the shot and the doctor told her no but I l know no type is 100% effective she told her mom about the sore breast and she told her it was naturally them growing and hormone changes I think she's pregnant could she be?