Pain between navel and breastbone

I've had pain between my navel and breastbone for at least a year.  Recently it has become intermittently worse, and sometimes radiates to the right and left sides.  All tests by my GI doc: CT, sonogram, gastroscope, colonoscopy, blood, all are negative. H,. pylori was negative 6 yr. ago.  My internist thinks it may be gallbladder, and suggested a HIDA test.

Any ideas?