(emergency) recently neutered kitten bleeding, but through his penis!

Hello! My 5 1/2 month old male kitten got neutered at the SPCA a week ago and he has barely licked the incision site during this time. This afternoon I arrived home and I quickly noticed he was licking his genital area. He had a very erect penis and I tried to catch his attention so he would stop licking. A few moments later I noticed he was licking again so I checked once more and noticed he had a little blood in his fur that seemed to have come from his penis and not the incision site. He is not erect anymore but he has been talking and eating a lot in the past half hour... I checked his litter box and it looks like he has not peed since the last time I checked this morning. Additionally, I discovered yesterday that he had peed somewhere that was nowhere near his litter box and he had never done that before in the two months since I adopted him.

I called the SPCA vet clinic and they said I should bring him tomorrow because they don't have any vets working this afternoon. 

Has this happened to anyone else's kitten? Should I wait until tomorrow to take him to a vet?

I didn't have an issue after Patches was neutered.  If you aren't sure that he has peed today I wouldn't wait until tomorrow.  Male kitties are prone to getting blocked, it may actually have nothing to do with the neutering if that is what is going on.