I'm 24 and i workout sometimes.When i was trying to put some lotion on my back the other day with my left arm trying to reach the right side of my back i felt a sharp pain in my breast going down to my left arm and leaving me with really bad pain.I'm going tomorrow to my doctor so she can tell me what the heck is going on.I can't even take deep breaths without having to feel the pain in my left breast.And then i kind of felt a knot on that shoulder,so when i touch that the pain starts.What did i do?Did i pull a muscle?I don't know if i just moved funny or if it's something serious but i guess i'll find out tomorrow.