I have my belly button and nipple pierced too. When I had my son I kept both piercings in the whole pregnancy. The doctor made me take them out during delivery though.
I'm 25 weeks and both my belly bars are still in,I think it varies on when and now much ur belly pops out.as for nipple I found at around 15weeks I had to get a longer bar cause the one I had was to short and beginning to be painful cause it was going inside my nipple. hope this helps
They have maternity belly rings, so you dont have to take out your bellybutton ring if you don't wanna.
My friend took out her belly piercing the week before she delivered. I think it all just depends on your tummy and if it's starting to hurt.