I recently acquired two kittens a male and female. They were born April 15th so they are 4-1/2 months old now. When I took them to the vet they scheduled them to be spayed/neutered the end of October. The female appears to be in heat. I called the vet to move the date up but they won't operate on the female until she's 6 months old and not while she's in heat. So Wednesday the male is going in to be neutered. Just in case he's nailed her, is he mature enough to get her pregnant? I sure hope not. I'm angry the vet wouldn't let me get her taken care of sooner.