No problem..I was going to add that another sign something may be wrong is if he should get a temperature, the shakes, etc. Not sure what type of shot it was but usually mine are extra tired afterwards. You may also want to check the area where he got the shot. It may still be alittle sore but just to make sure he hasn't gotten any type of allergic reaction or anything.
I'm sure he's fne though.....
Cuddle up with him tonight and give him extra snuggles & hugs.