The chances are minimal if you didn't ejaculate. The reason she could be feeling all the symptoms are hormonal. She could be approaching her period and pms symptoms often resemble pregnancy symptoms.

Another thing.....If you had unprotected sex just a week ago, there is no way she could be feeling the symptoms, as this is the time when implantation would occur and it is highly unlikely that she would expereince breast pain because of that. If implantation occured, she could be expereincing light cramping and spotting for a day or two, nothing else.