As this is a case of an accident and x-ray suggests it to be normal,there are chances of having any muscular injury(e.g. Supraspinatus muscle,Deltoid muscle),ligamentous injury or a soft tissue injury.But all of these are best visible in MRI only. But such cases can be assessed very well by manual testing of the body part involved by a well competent Orthopedic Physiotherapist.
My suggestion is to go to a physiotherapist(Specialised in Ortho) to get a conservative treatment and it is free from side effects.
1.Dont lie on bed with left side turn(i.e.on painful side)
Please visit a orthopaedist he will examine and suggest further management, such problems should not be neglected and management cannot be started on phone. It is beyond the scope of text consultation. Take care.