I have this rash all on my chest and little redish bumps on my nipples and my breasts feel like tighter and thicker all of a sudden. I have dermatitis so maybe that's the cause of the rash and bumps but I don't know. Then I got this really sharp pain next. Its under my armit above my breast in that region on my left side only. Now its moved over some to right above my breast in my chest on my left side. Its been constant for the past 3 days and I felt like crap all day today. It hurts to move my arm because it hits that spot and hurts it. I can't carry my books on that side because it hits that spot. I've been feeling it and haven't felt a lump or anything. It just really hurts and now my chest does too. I'm 16, girl. What could be wrong? Thanks.