"Showing" later doesn't usually have anything to do with baby's size. As long as your OB says your pregnancy is on track, there's no need to worry if you're not showing yet in your second trimester. (At your appointment, your doctor feels the size of your uterus—it'll be about one and a half inches below your belly button by the end of the month.)
Some women just pop out sooner than others. Assume this means you have stronger ab muscles than others and enjoy wearing your regular clothes a little longer. Before you know it, you'll be wondering how your giant belly grew overnight.
Excerpted from The Baby Bump: 100s of Secrets to Surviving Those Nine Long Months.
Plus, more from The Bump: