Stress is certainly possible, but I would look at other causes first.
GERD, an ulcer, or inflammation of the upper digestive tract are all possible.
You can consider an upper endoscopy or upper GI series to initially evaluate the GI tract. Blood tests to exclude the bacteria H Pylori can be done as well - as this is associated with some of the aforementioned causes.
These options can be discussed with your personal physician or in conjunction with a GI physician.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patients education only. Please see your personal physician for further evaluation of your individual case.