Dear shay: Skin on the breast is like skin anywhere else on the body and is subject to abnormalities such as pimples, etc. If this is new, it may be reasonable to watch it for a few days. If it gets worse or does not go away, you should have your doctor take a look.
YOUR SOUNDS LIKE WHAT MY DOCTOR JUST TOLD ME MINE WAS, INFECTED MONTGOMERY FOLLICLE, MY BOII LIKE THING IS ON UNDERSIDE OF BREAST, AWAY FROM NIPPLE AND AREOLA
I was given Bactrim to take for 2 weeks, apply heat. If not better it may have to be removed