Occasional chest pain. To oncologist?

I was diagnosed with Hodgkins Lymphoma and my combined treatment got finished on Jan 15th. I underwent 8 rounds of ABVD chemo and 15 sessions of radiation to neck. Of late I have been experiencing sudden pain in my left chest accompanied by burping. I went to oncologist regarding the same and he did a ECG to quell my anxiety. The results came back fine. I too assume that this is related to acidity as i don't have any other symptoms. Just for an assurance,I would like to hear if this is anything to be worried about or not ? As my pain comes Occasionally even now with burping. As its on left side ,am worried. NOTE- My echo was normal before beginning chemo and ECG was normal when I checked last week.