I was about 110 pre-pregnancy (and 5'7" - so a pretty tall frame, I don't know how tall you are OP), and I'm still not really showing.
As of week 16/17 DH and I decided I was really "showing". DH proudly tried to show this off to some friends this weekend, but they said it just looked like I'd eaten too many french fries :-P
My OB has also commented that I have pretty strong ab muscles, so I think that's holding things in pretty well. I'm still in all my pre-pregnancy clothes, and I feel like I just have a little tiny pot-belly going on. Nobody who doesn't know has commented on it, so I'd say I haven't popped yet!
You have plenty of time left to get big - and I'm sure by the end of it you'll be wishing for these more comfortable days!