My Son Is Having Chest Pain Which Makes It Hard

My son is having chest pain which makes it hard to breath. It started b/t 3 and 4 pm. There is a sharp pain when he burps or tries to take a deep breath. He was given qty (2) Tums tablets with water at 7:15 pm. I am being told by his godmother that the pain is getting worse - constant sharp. Laying down, sitting up against pillow, sitting on hard chair - nothing changes it.