Is Sore Breast And Delayed Period Sign Of Pregnancy?

My girlfriends period is late by about a week. Around the time she normally has her period she spotted which is kinda normal for her but usually her period immediately follows. We have not had unprotected sex I always wear a condom. She is not on any birth control however. Is there a chance she s pregnant? She has been camping on and off and her breast are sore which are usually indications that her period is going to start soon but it hasn t yet. One thing to note is I was looking at the condoms the other day and found out they were expired when I bought them by about 10 months. The condoms never came off or busted when having sex with the expired condoms and we only used about 4 before I realized. I am starting to freak out since her period is so late.