hello, i am a 18 year old girl 5'6 and 123 lbs. yesterday i noticed a small, hard little bump under my right breast on my ribcage. it hurts like a bruise would when i touch it so i thought that it would disperse and go away. today the bump seems slightly bigger (could be my imagination) and still hurts when i touch it. i just got out of the shower and started to squeeze the bump and when i did it released a little bit of puss and blood but the bump is still there. i put some antibiotic ointment and a bandaid on it. any suggestions as to what it might be?