I'm a couple days shy of 18 weeks, and I'm not showing at all yet. Maybe a slight curve when I'm naked, but once I put clothes on you can't tell. Is that pretty normal for a first pregnancy? When will I "pop"? At my 16-week u/s the doctor said that the baby was just fine size-wise, maybe even up to a week big. I'm 5'6", but long-torsoed (which means short-legged, unfortunately) for my height.
This is how I was with my first pregnancy. I didn't pop out until about 21-22 weeks. I didn't even get asked if I was pregnant until close to 25 weeks. We are all built differently and will carry differently with each pregnancy.