Why are you so okay with the shallow survival mechanics of this game but demand that pregnancy mechanics either be realistic or have an in-game explanation for why they're not realistic? You don't suffer any consequences for not eating for weeks on end. You never poop no matter how much solid food you eat. The explanation for these plotholes is simple: adding those features in the game would either be more work than it's worth and/or negatively affect the gameplay experience.
Also, the lack of overpopulation can be easily explained by the sheer number of mooks the average player kills. A nine day pregnancy would go a long way towards explaining the monster/bandit to NPC ratio.
I'm ok with it because this isn't a babysitting simulator, it's an adventure RPG. Which tries to be realistic and logical, I say try because it isn't perfectly realistic. Just look at how they first implemented pregnancy, it was an out of the way tact on event that makes you give birth to eggs, however, it doesn't break the in-game universe logic. The fast incubation and pregnancy period are explained easily enough due to the fact that you aren't birthing humans, and because you aren't you don't have to take care of them.
Normally I would be fine with your way of pregnancy but this game is not in-development from the ground up.
It is already finished. Meaning we have to keep that in mind with the way content is added. Otherwise, all you're doing is making an unrealistic wishlist for features that have no chance of being implemented. Like for example, I want a quest log, but I know that implementing one at this point in the game's life wouldn't be as easy as just adding new content. It would be reprograming each and every quest so that it gives you a main menu hint on where to go or what to do.
Now with all of that in mind, and seeing how he has already implemented his version of pregnancy content, can you honestly tell me your way of making pregnancy is feasible?