"Gosh, it seems like every woman I know is pregnant these days, are you pregnant too?"
Now what are the options here folks, on encountering this question (whether to you or to someone else)?
Personally I went with a bit of an assault on the questioner, along the lines of how is it any of your business, and you don't get to ask that, we tell you when we want you to know. Because the questioner is a good and long time friend of mine, who is very patient and familiar with my stroppiness, he didn't get defensive back and the conversation didn't descend into nastiness but instead continued in the light hearted tone he started with. Later on I patted him on the arm and told him I did love him but he really shouldn't ask people that. It was all ok, I think.
It never ceases to amaze me how people will ask stuff they have no business enquiring about. "Do you think your pregnancy will affect your performance?", "are you having fertility issues and is that why you haven't had children yet?", "you're recently divorced from a man, have you considered giving women a go?" These are all examples I've heard recently. The answers are none of anyone else's business. Really. And thus the questions should not be asked.
No one should try the "but I can't help myself, I'm so curious, and I only ask because I care" line on me please. I have friends I would love to ask if they are going to get hitched, when/if they are going to have children, but I resist. It's called self-control. You use it when you really want to yell FFS in the middle of an awful work meeting, when you want to slam the phone down on the family member who is being a dick, when you see something beautiful that you know you can't afford. You use self-control to protect yourself, why wouldn't you use it to protect someone you care about too?
If someone wants to share something with you that's personal they will do so. If you genuinely want to ask because you care you can easily say "look I'm not going to ask, because I don't want to pry, but if you want to talk about X I'm happy to listen."
Here endeth the lesson.