Your tummy should tighten when having a contration, I alway think it looks like the shape off the baby ie there is a big hard bit up top ( bum and legs ) and a small very hard thing down low ( head ) I have never had a bloating tummy but you never know.

as for babies fluffing I dont know maybe just some water getting squished out of the way or moved around but maybe they can as they can poo when in labor ( not that you want this to happen )