I have never done that, but I was with a friend who did. We were at the gym, and there was a woman we saw there walking on the treadmill quite often. She was slim except for a pronounced belly, and truthfully, there was no doubt in my mind she was pregnant. But my friend asked when her baby was due, and she said "I'm not pregnant, everybody thinks that, but I'm not," then my friend could not leave bad enough alone, so she said "well that's OK, that happened to me after I had my baby" how old is your baby? By that time the woman was pretty annoyed, she said emphatically, "I don't have any kids!"