Sore breast / late period

Hi ladies!
I have had sore boobs for the past 3 days, really bad.
I also am a few days late on my period... ¿Pregnant?
I'm getting kind of worried because my boyfriend of 4 1/2 years and I are going through a tough time right now, and he told me today that he wants to end our relationship.. I am in shock because I thought everything was going well with us...
I'm so stressed and sad right now I'm not sure what to do.
Plz help !