L.W.
We call that 'spaghettio syndrome'. It looks like a little spaghettio landed on him... We also use it often at family functions, saying that we now know for SURE that my husband is his Daddy. We are among girlfriends here, right??? :)
In seriousness, it sounds perfectly normal. I NEVER advise Moms against running everything by their doctor, however!! This board cannot replace medical needs for our kiddos! That being said, it was explained to me that as the baby gets "fatter", the groin gets especially fatty in some baby boys. So it's not really sucking in, per say, but just doesn't STICK OUT. Daddy calls it 'turtling'. Our pediatrician thinks we are nut cases. Hey; with three boys, I deserve to get a good laugh out of their "parts". I'm sure the same part will cause me much anxiety in the future, so I'm just laughing now while I can!!!!
Good luck!