Anyone have experience with their infant having a buried/hidden penis?

I have all nieces and girl cousins so boy babies are very new to me and I’ve never seen or heard of this. I noticed his penis seemed to be a bit hidden, but he’s a chunky boy so I pinned it down to that. I asked his doctor about it today at his 4 month appointment and she told me that if it still looked that way at his 6 month appointment she would send us to a specialist because she didn’t want to tell us wrong and they would know more. Not really sure if that’s really what is going on or if maybe as he grows it will come out more? Just hoping maybe someone here might have more insight.