Mother to be countdown pins? Cool.
First off lets get it straight, I hate the idea of an basically saying, "I am pregnant so give me something." However I love these gems, found on etsy.
They have a real sense of humour as you can show the World EXACTLY how pregnant (and not fat) you are. I would question if you could be an arse and change them all the time, but nevertheless a brilliant idea.
Each pin has the number of weeks left starting with 30 and counting down to THE week - so you really wont have to tell everyone how pregnant you are every five minutes.