Of all the irritating, frustrating, terrible, horrible, no good, very bad things people used to say to me while I was pregnant, the suggestion that I looked like I was "about to pop any day now" made my blood boil like little else. Even now, nearly three years after the fact, I get stabby just thinking about it. Saying a pregnant woman is "about to pop" are fighting words, in my opinion, because despite the carefree tone most people use when they say it, they're actually suggesting something really graphic about her body.
Reality check for people who don't bother thinking before they speak: popping is not generally a good thing, from the perspective of the thing that pops. I'll put it this way: If you're a man, would you want your testicles to pop? Probably not. And ladies, remember that creature bursting out of Sigourney Weaver's body in Alien? That's something "popping" out of a pregnant woman.
FFS, people, think about what you're saying when you talk to anyone, but especially pregnant women. Pregnancy is a blessing for folks who want to become parents, but pregnancy can also be a really nerve-wracking, stressful time, even when people aren't suggesting your body might be on the brink of a violent explosion. Pregnant ladies are just trying to get groceries or ride the train or whatever else in peace. They don't really don't need to deal with whatever asinine stuff random people feel like letting fall out of their mouths. So if you do tell a pregnant woman she's about to "pop," be grateful if you just get some side-eye in response. It could be worse, considering the following: