I have a pain under my left shoulder blade that causes my left arm to be numb & i can't sleep on my left side,i have nausea & sharp chest pains to my heart. its now 3 weeks with this pain but x-rays are clear yet doctors can't find a diagnosis.

Need better history: The nausea suggests that it may be GI (like GERD) but that symptom can also be heart related. Because of the pain and numbness, I suspect muskuloskeletal. Were you exercising or lifting? In a funny position for a while. Any trauma? Are you a smoker or drinker? Does food or deep breathing aggravate it? Would check basic labs and maybe an echocardiogram and even consider an upper endoscopy.

Further workup : Certainly would need further workup to rule out potential cardiac, pulmonary, and spinal causes. An X-ray is not terribly sensitive to evaluate you for the symptoms you are describing. Further work up towards obtaining an accurate diagnosis should be pursued.