Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. 1. As your cardiac test came back negative thus the possibility of Acute heart attack or Angina can be safely excluded, however, get a Cardiologist opinion in case symptoms are not improving or worsen further. 2. Consult with a General surgeon, because as I m unable to examine you directly it probably could range from heartburn/ gallstones/ appendicitis to peptic ulcer. [might go for Ultrasonography of abdomen] 3. Later, you can check with a Gastroenterologist who may be able to diagnose the cause of your stomach pain and ask for necessary examinations like endoscopy, blood examination, X-ray, CT scan & MRI, till then - avoid undue mental stress - avoid spicy/oily food and reduce caffeine/alcohol intake - drink lots of water, both with meals and in between them 4. Although it could turn out to be simple indigestion or heartburn which might get benefited from OTC medications, but consult with your primary care doctor since sometimes there may be an underlying medical condition/situation which needs appropriate treatment. Hope I have answered your query. Let me know if I can assist you further.