Testical problem

This is a question about my boyfriend, I am worried about his long-term health.  If he caught me writing this, he'd probably die!  But I cannot get him to go to a doctor so I was hoping to get some advice here.

When I was first intimate with him, I noticed he has very lopsided testicles.  It's hard for me to describe, but one of his testicles feels as if it's lodged up inside his scrotum.  It's so far up there that if you look at him, you would think he only has one.  But he showed me that if you touch his scrotum in a certain way, you can still feel where it is, but you can't really move it around.  The other testicle hangs freely, like normal.  

He also has two scars that are above his penis, when I asked him about it he told me that he was born with undescended testicles and had to have surgery to bring them down.  He told me he had a hernia too, all of this happened when he was four.  He didn't have his testicles fixed or his hernia fixed until he was four.  The scars are still there.  He said the one normal testicle eventually dropped into place but the one that is "lodged" has never come down completely.

I was baffled by all of this because I had never heard of any of this before.  I did a little research on the internet but the only thing I found scared me.  I read things about complete infertility and increased chances of testicular cancer because of having undescended testicles.  Everything I read said that the surgery he is talking about is normally done right after birth, so his story that it happened when he was four years old doesn't make sense to me.  

I have asked him to go to the doctor because I was worried about him, but he refuses.  He's too embarassed to go and ask questions like these.  He isn't in any pain so he doesn't think there's a problem.  Maybe there isn't and I am just overreacting.  Opinions?