What Causes Sore Breasts And Nausea Just Before A Menstrual Period?

My boyfriend and I had intercourse 2 weeks ago in the beginning of the week and at the end of the week. We did it the week my period ended. The following week I had something that seemed to be implantation bleeding, but it could be something else. Now my nipples are a little sore, my sense of smell is heightened & I m pretty emotional. My period is supposed to come in about 3 days, but its always irregular. What does this sound like?