From what I have read online Including this site it is not uncommon for this to happen after receiving a vaccine. I really think that is what the lump is. I am taking him to the vet this week.
I recently about three weeks ago adopted a three month old kitten from the shelter. He is happy and playful and eats right and seems fine but as I was petting him the other day I felt a small lump on his right back leg under the skin. It doesn't seem to pain him when I touch it and it is not...