Pregnancy Etiquette

Jocelyn
Why do people say stupid stuff to pregnant women?
In a department meeting Full of 50+ people someone asked me when I was due. When I told her she said are you having twins? No I'm not. Wow you are growing mighty fast. 
Really??? Regardless of my size is that an appropriate thing to say? Of course I'm going to take offense. But really I have 10 weeks left and am measuring 3 weeks ahead so yay I get it but seriously you never make comments to a pregnant woman about her size or tell her horrible birth stories. 
Ugh.... Ok vent over.