jessimaca- this is my 6th pregnancy (3rd baby) and i don't start showing until about 20 weeks. people who show sooner arn't actualy showing 'baby'. the uterus moves up out of the pelvic bone, which causes the other organs and muscles to shift, which makes it look like a baby bump. some people do this sooner, some dont.
i have a long torso, so my ther stuff has a place to go instead of "out". so i'm with you, jealous of all the cute bellies! but dont frett, you'll get one too.
p.s. i have aq good friend who never showed...with either pregnancy. if she wasnt paying attention she could have been one of the ladies on "i didn't know i was pregnant" because she was 9 months preggo, and she didn't even look like she had had a big meal. yikes!