Hi, I was 5 ft and size 6/8 when I fell pregnant with my little girl, and I started to show immediately (but only to me), for months I had a belly, but the girls I work with told me I didn't, because my belly was soooo flat (oh the days), before I was pregnant, that a slight bump wasn't really that noticable to anyone else but me.
Only, even before I found out I was pregnant, a top I had bought 7 days earlier no longer fitted me.
Hope that makes sense. Congrats on your pregnancy by the way.