If the bruise is behaving like a regular bruise and going from black and blue through yellow and a whole rainbow of colors as it heals, then the lump you feel is probably blood below the surface of your skin that will gradually be reabsorbed as your body heals. If you have been taking certain vitamins, aspirin, other NSAID types of pain relievers like ibuprophen, you may be more prone to bruising because some vitamins and medicines can thin the blood. 

If the place isn't changing colors, or if it's gone from light pink to darker reds and purples, you need to call the doctor right away to have it checked out.  It could be an infection or a rare type of breast cancer called inflammatory breast cancer.  I don't know what to make of the skin peeling.