I used to roll my eyes when people had a guess at what I was having, we never found out so I'm sure we had people laying bets.
But I must say with DD, she was all hips (Kinda low), I put on 18kg, but I was all round the hips, rounder face etc.
With DS put on 10kg and I was WAY out the front, you couldn't tell I was pg from behind. I had Sciatica with him he was a big ball, sticking right out.
If we have a 3rd I'm having bets with myself that I will be able to tell what I'm having.