my advice is log it with the police, it's only one form, very easy to fill out. this covers you just incase. also, i wouldn't bother with the hospital if you are basically ok but i would make the phone call to the local GP and get yourself checked out, just to be safe.
bike wise, make them pay for it, if it was their fault, they should pay. simple as that.
with out going in to boring details, i think what i have written is important because:-
i got knocked off at 8.15am, not my fault, very lucky escape, except for the bike, limped to work after getting the guys details and he admitted it was his fault. by the time i had got to work, he had been to the local police station and claimed i fell infront of him, phoned his lawyer (apparently) and his insurance. cos you do all that if your innocent don't you?!
i got lucky, he lied to 3 people with 3 different stories so when
www.cycleclaims.co.uk got to talk to him on my behalf by 11.30am that morning they knew he was lying. i then filled in the police form. ended with the bike getting paid for about a month later from his insurance.
basically the moral is, most people out there are good people who are mortified by their own stupidity of hitting you and will happily pay for the damage, BUT there are also complete tossers out there aswel who just want to get away with it. don't take the risk of not getting yourself and the bike checked out properly, and backing up your story with a report.
also with the injuries, shock and adrenalin makes bruising and aches not hurt so much at the time, a while after or the next day is when you start to feel bad.
edit, for some reason the link to cycleclaims goes somewherelse, but that was definately the people i used. i know the bcf use someone similar though.