21 weeks and no bump?

I had my anatomy scan last week and Dr. said everything looked great Baby is actually weighing 5 oz ahead of schedule. I have no bump at all .. a slight pudge lol but no bump. Everyone keeps making comments on "are you sure your pregnant?" "I'm worried something is wrong with your baby!" I am 5'11 and weighed 170 pre pregnancy. Anyone else like this? I see other people's bump pictures and they all look so cute and pregnant and here I look like I ate a few too many carbs last night. This is my 1st pregnancy 🤰