What Causes Persistent Chest Pain And Frequent Burping?

I went to the ER twice and my family doctor all in the last 10 days with chest pain and a lot of burping and have been treated with GERD and felt some relief. The chest pain has remained for the most part on the left side of my chest for a few days it has felt sore along with some burping. Now today the area under my left arm has felt sore and I feel what I believe is fluttering. Any thoughts?