I'm starting to show, but not so much that my kilts won't be able to fit. I usually wear them with the buckles all the way buckled so I can easily add more side room by loosening up the buckle. Also, I don't really wear them on my waist, sort of under it. So they will fit fine.
I haven't reached that stage where you see a pregnant woman and think "oh my gosh she's going to bust yet". Thank goodness!