By preference, yes. As another poster mentioned, it seldom results in even a big belly, or maybe a epilogue mention, let alone more content, so I don't get much for it. But I prefer pregger games when they exist.
It depends if game is punishing you for that. If not almost always. I guess only if person in question would be hideous I wouldn't want to do it even if there would not be any punishment. But also games barely use pregnancy outside of "Hey you got her pregnant" information. Sometimes if stars align they will also be pregnant sex but this is almost always maximum we get.