How long do stomach ulcers take to heal. on medication but still very sore pain in my stomach when i eat?

Depends.: it depends on many factors, including the initial size of the ulcer, what medicine you're taking to heal it, whether H pylori is present, and what caused the ulcer in the first place. In general, however, if you're not starting to see some relief within 7 to 10 days of starting medication for a proven ulcer, I would call your doctor back. Good luck.