Pippin also had an undescended testicle. When I brought him home, my vet said that it was possible he was either retracting it because he was scared or that if it was undescended it was possible that it would come down on its own. Well, it never did so he ended up with two little incisions instead of one. It was $50 for the extra procedure to find the testicle, and he recovered in no time flat. So no worries, everything will be fine.