I am a male, 29 years old, athletic, and in good health. For the past two years, i have been experiencing a dull pain in my chest on the left side after i have been sleeping for some time, and sometimes the pain radiates through the middle of my back. I've checked many forums, and have yet to find out anything. I've also had xrays with normal results. any thoughts? i do not have GERD or any sort of acid reflux. I want to look into getting an ECG, do you recommend i start there?