I have sharp pain in my left shoulder blade that moves to my arm pit and should what can i do for the pain?

NSAID: There are many possible causes of pain in the shoulder blade - for example, a strained latissimus dorsi muscle. A non-steroidal anti-inflammatory drug (NSAID) such as Ibuprofen (advil, motrin, etc.) or Naproxen (aleve) can help, but if it is severe or persists more than a week, you should get it checked by your physician.

See a doctor: Pain is usually a signal that something is wrong. If this pain has been sticking around you should see a doctor and be checked out. Most of the time it is something fairly simple but you do not want to ignore something that could serious.