Stomach pain in pit of stomach, what's wrong?

Lots of things...: Our brain can't tell the difference in pain signals from heart, esophagus, stomach, duodenum, liver, pancreas, bile ducts, liver, or gallbladder. So illnesses of any of those organs causes upper abdominal pain; gallbladder is most common. A good doctor will ask questions like what brings it on, makes it worse/better, how long it lasts, associated problems. See dr. ; get proper diagnosis; good luck.