I Fell 4 Months Ago And Fractured The Ball Of

I fell 4 months ago and fractured the ball of my humerus, but my pain has always been in my bicep. The bone has since healed well as confirmed by x-Ray and MRI. My bicep muscle continues to cause me pain and at time is quite painful when it feels as if it suddenly contracts for no reason. MRI looks fine per my ortho MD. Any suggestions as to the cause of the pain besides referred pain?