Belly button popping during pregnancy

Not everyone's belly button will pop out during pregnancy! It's simply the act of your stomach expanding so much that it pushes the belly button out, but sometimes there are women who have a real deep innie belly button or just doesn't have as big of a tummy than others so they don't have belly buttons popping out. Either way, both are normal and your outie will go back to an innie after giving birth (since your stomach will reduce in size too).