I'm not a thin woman by any means (around 220 lbs), but I literally couldn't button my pants at 5 weeks I had to break out my maternity clothes. My chest has grown a size already and my stomach wont fit into any of my size 16/18 shirts or pants. I was worried about twins, but there is only one. So it has to be baby bloat and early showing. Under my tummy fat (tmi, gross I know, lol) is all hard.