Muscle memory ;) I didn't show til 16-17 weeks with my first. I started showing between 10-11 weeks this time with #2. This was at 10 weeks on the left with the tiniest little bump after my bloating went down around 9 weeks. And I'm 10+3 on the right. Woke up and it was just there. Lol. Now I'm almost 13 weeks :)