I'm 38+2 and a bit confused!
Pretty slim 8/10 pre-pregnancy, not put on much weight so bump has always looked big, until yesterday, when it seemed to sink inwards while driving back from a food shop 
It looked for a moment like the baby had been teleported out!
I can stick it out when if I try, but have been naturally holding it tense, and if I suck my tummy in you almost can't tell I'm pregnant, which is really weird. My first thought was that the baby had engaged but I don't feel like there's a watermelon between my legs or anything; although I am seeing a lot more and managed to wet myself so spectacularly the other day that DH thought it was my waters (he made me call the midwife, who said it sounded like a bladder control issue 
).
Movement is not reduced but it is muted, as if he's in a position where much of his movement is padded, although when he does poke a foot out of my side it is as strong as ever!
Braxton hicks a couple of times a day and a bit of diarrhoea, but no other symptoms beyond a strong as strange urge to spend two hours scrubbing the vinyl in the kitchen (completely nonsensical as laminate is being fitted tomorrow!) and to repack my hospital bag several times.
So... any idea about the strange absence of bump? Am I still good for another few weeks?