I am assuming that you had an upper GI scopy. I would suggest that you pay another visit to you doctor for this problem. As pain after an endoscopy
can occur as it is an invasive procedure. It could be just a pain that can be treated with pain killers , but in case it is any other complication of an endoscopy such as bleeding or tear it is advisable to get it checked immediately. Your doctor will be able to advise appropriate treatment.