zero bump -- 12 weeks

Katie • Baby boy- April 2017
I promised myself I wouldn't get worked up about this at all, but here I am! I am 12+1 and have no bump. Not even when I'm laying down. It worries me as things i'm reading say your uterus is at your pubic bone now but I don't even feel it there. Anyone else?
I have my nuchal on Wednesday and I'm so scared something is going to be wrong.