I bought very little maternity stuff last time - a pair of jeans (H&M) and three tops on eBay, I think! I mainly lived in (normal) leggings and loose jumpers/dresses. I worked in a much more casual office then though. I also showed very late, i think because I'm quite long in the torso. Planning to buy a few nice bits this time around, partly because it'll definitely be my last pregnancy, but I'll wait and see when I need them first. I know second babies tend to show earlier/bigger, but I'm not sure how the five-year gap might affect that general principle anyway. As soon as I can't get into my current stuff, I think I'll switch straight to maternity rather than sizing up or anything.
That's so sweet that you've got the knitted stuff from your own babyhood, onceupon! DS had my newborn babygros - we do rapidly-fattening babies in this family, so me, my sister and my DS, all 7lbs at birth, only fitted them for a fortnight each! Looking forward to putting this baby into them too, however briefly!