me too. when i was pregnant for 5 months, nobody knew that i was pregnant. only after i started wearing maternity wear did my colleagus realize that i were having a baby.
it is related having a girl or a boy? people said having a girl is earlier to show, boy usually won't show until 4, 5 months. It is true to most of my friends.
I have a small tummy and it show starting in 2.5 months.