I have a mass in my left breast, picked up by routine mammogram. Does the word mass mean it's definitely cancer? I'm worried sick and scared. The word mass is making me fear the worst. Had another mammogram yesterday, followed by ultrasound scan, and then 3 biopsy's taken. Have to wait 2 weeks for results. My breast is really painful after the biopsy, pain is going into my shoulder, never had the shoulder pain before, is this normal after a biopsy.