The past few days i have had a sharp, stabbing pain in my left bicep- it happens a couple times a day, but then goes away. should i be concerned?

A few things: If the biceps is tender to touch or pain is increased with using the arm then the issue is likely within the muscle or arm itself. If the pain is not reproduced with movements of the arm or with feeling the muscle it could be a referred pain. This would commonly be from the neck or even a trigger point. Not sure of your are, but a cardiac source should also be considered. Go get checked out.