One thing most are forgetting. Is that it takes several months before any signs of pregnancy. And as far as I can tell, it has been at most a couple weeks since MC started having sex with everyone. So even if he does have the super sperm, it takes time to show.
To be fair, I think there's a misunderstanding about the whole pregnancy thing, especially with the M7™.
Early on, there were a few times we were given a specific choice to make some "side" girls pregnant, giving people the satisfaction of doing the deed on their terms.
It's been stated in the forum here (by known beta testers and not refuted by Moon) that the paths for Nana, Jamila, Asuna, Shizuka, Amy, Liz and Kat are all set in stone, with only some of the "stronger" kinks being avoidable. So there's every reason to think that at least a couple of them are actually already pregnant, or will be soon.
But that doesn't mean we're going to be told that the event is happening, because it won't be a choice.
What people are really asking isn't to make the girls pregnant, they're asking to be ALLOWED to make the girls pregnant. They don't want it to just happen without their consent (controversy intended).
There's also the possibility that Moon has expanded some of the M7-Locks™ to some of the other girls. For instance, you have a choice whether to make a deep dive into the O'Reilly clan, but once the quartet secure your services, you seem to be in for the long haul ... I would say the same about Aaliyah and Jada, and of course Tanya goes without saying. So who knows how many more times we'll even be asked if we want to make a girl pregnant or if we've already made those choices?
Anyway, hopefully it's a long way off, but I'm looking forward to the Epilogue.
EDIT: Oh, and don't trust the Relationships Tab ... it doesn't seem to have been updated for at least 4-5 releases, maybe more.