what if you just looked them straight in the eye and say "i beg your pardon''. and then wait for them to say something further and just stay silent, but look directly at them. i reckon they'll be the one feeling rather uncomfortable pretty soon. and you could just end their discomfort with a sarcastic "rrrriiiggghhhhttttt''.

if i had the guts that's what i'd do when i get the 'oh my god you're so big, sure you aren't carry twins'. you just can win hey! soon you'll get the comments about you belly and whether or not you are showing etc. oh the fun of it all!

and big congrats on your pregnancy love! we hope to achieve a similar feat