Sarah, I don't know where you could have put on 20kg either. I had a sneak peak at your website and you look fantastic. Maybe it's a 20kg bubba only joking, but really you look great, I'm sure you won't have any problems losing the new kg's once bubs is here. I too lost almost all the weight I gained while pregnant with DD, shortly after she was born (except 2kg too), I put it down to BF too.
Not long for you now, how are you feeling?