The skin of the breast is like the skin on any part of the body and subject to many abnormalities.The areola and the nipple area have sebaceous glands which can get clogged and form a pimple like lump.You may apply warm compresses,use antibacterial soap and see if a whitehead forms.If it does,apply a little Polysporin and it should go away in a few days.
I don't think that this lump has anything to do with breast cancer,but it would be better to have your doctor take a look at it, particularly if it becomes inflamed,larger or doesn't go away.
I hope that it's really nothing to worry about.
I had something similar. It was a cyst. Ultimately it got infected and I had a dermatologist get rid of it.
You are scared because, like most people, you think the worst. Nevertheless, keep your eye on this lump to see if it grows or changes.