I was wrestling with my boyfriend and he grabbed me from behind and squeezed me very tightly around my rib cage, with my arms down by my sides. He tends to underestimate his strength, and something popped. When I woke up the next day I noticed my ribcage was extremely sore, as well as the side of my left breast where the pop was heard. My left breast feels different than my right in that area. It s like there is extra tissue now, almost a knot. Any ideas?