Awww bless mines half in half out at the minute but think it's going to come out properly
My belly button has popped out, i had an "innie" belly button before i got pregnant and it was about 5 months maybe a bit more when it popped out properly. I think its really funny and i always gently poke it and my baby moves round, so cute. And yes it will go back in after you give birth :)
I'm on my 3rd pregnancy and almost 33 weeks in and mine has never popped out.
Im 36 weeks and mine has been trying to come out lol, it i push around the edge of it then it pops out, its so weird and cool at the same time lol, but yes it will go in but it wont look the same after even if it doesnt fully pop out bc if your belly being stretched