What Causes Tender Breasts And Heavy Discharge?

I'm on methotrexate for RA, 12.5 mg per weeks. My periods have been pretty bad but short, and regular. This month I've had uterine fluttering/heavy clear discharge, but not smelly or itchy, my breast are very tender. My hus and I are very careful, but I feel like I'm 4 months pregnant over night