My kitten only has one testicle and he got fixed this morning, will he be in a lot of pain after 2 surgery?

My little dude is only 7 months old and he got fixed this morning, the problem is he has only one testicle so doctor needs to perform another surgery to find the one that didnt drop, this afternoon, my vet called us said the surgery went fine but he needs pain killer bec they went through his muscles to find it, I am very worried if hes gonna be in a lot of pain, has anyone had the same experience? will my kitten be scared of us, his surroundings?