Soon To 22 Weeks But

This it my #3 pregnancy. It's so much different with previous 2. I'm going to 22 weeks the tummy is so small. It looks like 4 month preg tummy. But I do have bad morning sickness for the first 4 month +. When I did the detail scan last few weeks doc say everything looks fine. Any mum also have almost same issue? I'm just afraid when baby is out the size are too small.