Pain upper left side under rib cage just below left breast. mammogram, x-ray, ct scan, colonoscopy and urine all fine. help.

Muscle?: May be a muscle strain, see if it gets better after safely taking some ibuprofen.

Check your ribs: If you have a rib out, you could have the pain you describe. Seek out a D.O. (osteopathic physician) or a chiropractic physician to evaluate your ribs to see if that is the source. Also, your stomach and your esophagus are in that area. I didnt see that you had an egd. Reflux, and gastric or esophageal ulcers could cause the pain.

Rash?: Look for evidence of a reddish rash with vesicles. If present, you could have shingles. I have seen a woman of your age who presented with similar symptoms and thought she was having a heart attack!