Do you mind if i ask how tall you are?
With my DD Ava i didn't show much at all, i was starting to worry about it and asked the midwives, they said because i am quite tall i had a lot more room for bubs to hide than a lot of other ppl.
It's not always the case but i looked like i had eaten two roasts rather than was having a baby.
I'm now pregnant with #2 and am 18wks today, i am showing a fair bit more than i did with Ava but if i'm not wearing tight tops i just look a bit rounder than usual.

Don't stress, i'm sure you will pop out and look pregga's in no time.