Hello and welcome to HCM. As you are known diabetic,it is necessary to do ECG ,stress test to rule out coronary artery disease,one of the silent complication of diabetes. I recommend- -Keep diabetes within control by timely medications and follow up for checking blood glucose control and ruling out complications. If all comes normal and pain persists or is associated with other complaints like fever,nausea,shortness of breath,further assessment through chest X ray and USG will be required to rule out conditions like pleural disease,pulmonary embolism ,gall bladder disease etc Hope this information helps. Thanks and regards.