Find a new doctor... if he/she isn't (at the very least) alarmed by this and refuses to see you in a timely, find someone NEW!
Have you received an MRI or CT scan yet?
A cardiologist will be able to tell you if this is heart-related. Pain in the left shoulder area suggests possible heart involvement. Zak_Han offered good direction here... cardiologist first, orthopedist second. Ortho will likely order the MRI/CT imaging studies for a closer look.
Why would you think a heart specialist? I will mention this to my doctor - Thanks!
Perhaps you need see heart specialist,if it's fine,then see orthopaedic doc.
Best wish!