I could have written the OP too (sorry, a little long after the fact, but just wanted to add my 2cents on this topic)!
I am almost 6'1", with a long torso. I was about 240 pounds for my first pregnancy. The first person that asked me when the baby was due was when I was 1 day away from my due date. My belly had a nice round shape, but since I'm a pear shaped person, I think I finally just looked proportionately heavy (around 275 pounds at birth). Also, my son weighed 7 pounds, so not huge, so my belly never got really big. I also have wide hips, so those things all together made for a small belly size. My belly button never popped out, I never got stretch marks, and I was also back to my prepreg pants within a week of giving birth. The belly just vanished after the birth.. so there IS an upside to all this!
