Gallbladder pain can be felt in your back and radiating up through the shoulder blades, it did for me...Did the doctor order an Ultrasound or HIDA Scan to check for gallbladder? Before my gallbladder diagnosis, I went to the ER twice for EKG's and 2 stress tests to rule out a heart attack!
If it turns out to be your gallbladder, try eliminating fats from your diet, no salad dressings, butter, cream, whole milk, etc. as this is a trigger for pains. Also for me, tomato based sauces, chocolate, coffee, tea, orange juice, anything acidic caused me great pains and digestive disorders even still after surgery.
I hope you get some answers from your doctor soon, let us know how it turns out.