Unilateral breast pain manifested as localized, sharp, throbbing, stabbing, or burning, is known as non-cyclic pain (does not vary with the menstrual cycle).
It can result from breast trauma, breast cyst or fibroadenoma, arthritic pain in chest wall (muscular or bony problems of the chest wall) and in neck, which radiates down to the breast.


Breast tumors, cancer and lumps are an uncommon cause of this kind of breast pain.
When the breast is dense the mammogram can't give correct answers, and an ultrasound specifically focusing on the area of pain can be suggested.

It is very possible that this breast pain originates from your chest wall.
As a fibromyalgia sufferer, you may have special problems with chest and upper body pain known as "thoracic pain and dysfunction".
Acctually, costochondritis, condition with a chest wall muscle pain, is a localized form of fibromyalgia.