That is to be expected. Accidents cause the body to go into a sympathetic response, and the sense of pain becomes restricted. Once the body has gone through the parasympathetic response is when pain is to be felt. I was told this after my car wreck. Thankfully, I only walked away with bruising.
I forgot to mention this yesterday, but three other interns and myself (I was not driving) almost smashed into a bison yesterday evening

. A Ford Focus (the government vehicle) hitting a bison head-on at 60 MPH would've been very bad for both parties

. That would've been bad, two GOF wrecks in one day

.