My deltoid feels uncomfortable when I attempt to lift my arm, what is wrong with it?

I was biking to work this morning when a cab pulled out in front of me, leaving me with the choice of being pinned between the cab and a pillar or crashing into the pillar. I chose to hit the breaks and the pillar. At impact with the pillar I hit my right shoulder but it didn't hurt, it was just sore. Now I am at work and I notice its uncomfortable to lift my arm. I don't have pain at the moment but my range of motion is definitely limited. Did I strain my deltoid? or worse did I tear something? The impact was as if something came down on my shoulder. Should I go see my doctor?