I think my kittens teeth bled when I was getting him used to his toothbrush.

I adopted a four month male kitten named Teddy (short for teddy bear). Last night I put some cat tooth paste on the smaller end of a pet toothbrush (it's double sided), and let him lick and bite the tooth paste off, but when I pulled it  back out of his mouth it was slightly pink . The whole toothbrush wasn't covered but I could still see it. Should I be worried?

Did he bleed even though you didn't actually rub his teeth or gums? That would seem strange to me. A little blood from rubbing teeth that haven't been brushed before wouldn't be odd, IMO.

He is probably teething. This is about the age that his baby teeth fall out.