I think you've hit the nail on the head about how John Heavens has resumed his attraction to his wife, as Jstforme said earlier. However, I still believe that in the end there will be no sex between the two in any of the possible routes, either due to a "timely" call from the missing Silvia, or due to a timely interruption from Chloe, that if I'm not mistaken, in all possible routes she has been within her house during the evening of Day 20.
If the last possibility happens, it's most likely that Nicole argues with her husband at that point, causing Chloe to want to snoop around and one of them will hear that their daughter is getting closer, forcing John to get dressed to avoid the possibility of his daughter seeing him naked. Perhaps John expressly mentions Nicole's close relationship with MC, something Chloe would listen to, arousing the suspicions she had on the night of Day 11.
As for what is mentioned about the birth control pills that Nicole bought on Day 14, I think it's feasible to say that Nicole hasn't stopped taking them since she bought them (the trip to Little Big Pond lasted a whole day plus a few more hours at the most; besides, it is most likely that she brought the pills in her bag), but these pills are not 100% effective, because there is always a small percentage of error. Therefore, a future pregnancy cannot be ruled out (especially considering that from the moment MC fucks Nicole, there is a new indicator that mentions how many times MC has cum inside Nicole), but I think it will take time to appear (especially if each new part only exposes one day of the game).
However, the simple possession of birth control pills in Nicole's possession could confirm the suspicions that John may have about whether his wife is being unfaithful to him with another man, if he discovered them in her possession when he left those green panties as a present for his wife.
On the other hand, I don't think MC will run away with Nicole either, at least not before showing Nicole her husband's dirty actions, both work and love. And not to forget what that could do to Chloe, who by then should start preparing to head off to the college of her dreams (After all, Nicole agreed to all of this so that her daughter would pass those exams with flying colors so she could go to that university).
However, there is one variable that we have not mentioned: the reaction of MC's parents when he returns home and they discover him beaten and bruised after the beating inflicted by Beeman. MC will most likely mention to them that he was attacked by a robber during an attempted robbery, but even if they buy that lie, they will want him to go to the hospital, which could make it impossible for him to make it to the breakfast the next day, a date that Nicole finally agreed to go.
All this could lead both to the possibility that one of his parents discovers his secret affair with Nicole or that MC finally discovers the secret that his parents are hiding from him (taking into account how they seem to want the end of the relationship with Chloe, I suspect that MC's father has been offered a new position in another city or he or his wife have some health problem that causes the family to move to another city).
Finally, about Nicole throwing up, McRichard has already shown the screenshot. I think around the time Orb wrote that April Fool's Joke, the game
Who's the Father? was being talked about a lot.
