I'd get it looked at by a Doctor -- i got bit my my friends cat (he got me good too, right down to the gumline into that part between your thumb and forefinger), and it started out like yours (red and puffy), and went into a full blown infection needing antibiotics to clear up

Definately take care -- my friends joked with me for a while afterwards that Orange Cats must be carriers of Tetnus since they're Rust coloured

** yes, I know, Tetnus and infections aren't the same thing -- you may want to make sure you're up to date on that shot as well **

Good luck with all the kitties too -- its really fantastic that you're helping out all these little kittens!