Hi,
The chances that this is breast cancer is very doubtful..A bump on or near the nipple could be an infected hair follicle or a blocked sebaceous cyst.
The nipples contains glands like the skin of the face. If the pores get clogged and secretions accumulate, this can become infected and manifest as pimple.Don't touch it or try to squeeze the bump, just keep the area clean,apply warm compresses and see if it goes away.If it does not or you notice redness and the bump getting bigger,then you should see your doctor or a dermatologist, who can prescribe some type of medication to resolve the problem.
Best wishes....