Hi CarrieBrady and welcome to the forum! Did you read through Fibro 101, the very first post on this forum? There's lots of good info.
I can get burning just about anywhere, and yes, that includes my armpits and breasts. I do get yearly check-ups and mammograms, and that has relieved my mind. It just seems to be another weird fibro issue I have.
I believe this topic has come up before. You could always check in the search box above.
For a long time, I've found it impossible to sleep on my left side because of the odd sensation I get in my breast and just under. It's been checked out, but nothing seems to be going on---maybe just weird nerves in there. It's good you checked it out with your doctor, and I would guess you likely have mammograms, so that may ease your mind.
Nerve pain can be odd and even feel like a shock. It can even sometimes feel like your hair hurts and my doctor said yes, it's nerve pain. I take Neurontin for that sort of thing.
Maybe others will weigh in also. If it continues to bother you, recheck with your doctor or consider seeing another doctor who may be more helpful.
"When you encounter difficulties and contradictions, do not try to break them, but bend them with gentleness and time."
St. Francis de Sales