Not to beat a dead horse because I'm sure the dev has heard this to death by now, and I genuinely really like this game so far, but it really seems like pregnancy would lift this game so much, especially with how much it fits with, and is even talked about in, the story.
It doesn't have to be right away, it doesn't have to be all at once, but it would be absolutely huge. The game really doesn't need many more girls, they're A LOT to keep track of as it is already, and there's only so much different stuff you can add with the same girls. Sure, we can start delving into more threesome/group scenes and maybe some fetishes but I really think that, eventually, girls getting pregnant just makes too much sense.
Maybe, at some point when each girls has been introduced and has a decent amount of content, each update could have 1, max 2 girls with pregnancies. It doesn't have to be more than that.