I have been having pain in my back near my left shoulder blade for a few weeks. The pain then would go to my arm and neck and even the front of my chest all on my left side. I went to the ER because I was concerned about my heart, even though I am only 30 years old. They did an EKG , blood work, a chest xray , and a CAT scan and they said everything was normal. They told me that heart pain would often be more on my right side and sent me home. Everything has been the same the past few days and then today I got that same back shoulder blade pain, but this time on my right side. Should I be concerned this is something more than muscle or nerve pain and insist on having more tests done?