Why does my baby's nose look so different?!

Melissa • My husband and I were blessed on November 19 2015 with our son Nolan! Currently pregnant with baby #2 👨‍👩‍👧‍👦
All of these ultrasounds are from my anatomy scan at 18w2d. Why does his nose look so different in each of the scans it looks like it's a different baby! Lol the last 2 look the most similar to one another but the first one looks completely different any one notice this with their ultrasounds?