NEVER!!!! I was helping out in the Sunday school at my church this morning and yes, the dreaded assumption was made. The woman in charge of organizing the helpers was telling us where to go when some poor man asked for the last space with a chair because of his bad back.She apologized to him and said "Sorry. I have to give the chair to the pregnant lady." AHHHHHHHH!!! I pretty much could have died right there. The hunched over chairless volunteer knew I wasn't pregnant but seriously, what could he say? So, with my face bright red, I patted my belly and said 'thanks'.
I guess it's surprising that people don't say things like this everyday. I weigh at least 20 pounds more than I did on any of my delivery dates.
What's even worse is that the woman that made this grevious error actually knows the hubs much better than she knows me (which is obviously not very well). It was because of this that I had to let him know that if asked, I'm due in June.