A plot twist could be that the pregnancy is part of a prophecy that neither of them knew about. This would add an element of fate and mystery to the story. They would then have to figure out how this prophecy fits into their lives and the future of the wizarding world. It could also lead to them uniting different factions within the wizarding community who either support or oppose the prophecy.
One possible plot twist could be that the pregnancy is the result of a magical accident or spell gone wrong. Maybe they were working on a new charm and something unexpected happened. Then they have to figure out how to deal with it while keeping it a secret from their enemies in the wizarding world.
One possible plot twist could be that it was all a dream or a vision caused by a powerful magical artifact. Harry wakes up thinking it's real, and then he has to figure out what the vision means. Maybe it's a warning about some future danger related to Severus, and the pregnancy is just a symbolic representation of something they need to protect or create together in the future.
One possible plot twist could be a magical mix - up. Maybe a spell gone wrong during a joint mission between Harry and Fleur. For example, a spell that was meant to protect them instead created a false pregnancy - like situation for Fleur. Another could be a prophecy that was misinterpreted, making everyone think Fleur was pregnant when in fact it was a sign of something else entirely related to the magic in the wizarding world.
It could be a story where Luna has a premonition about having a child with Harry. They initially don't believe it but as time passes, some strange magical signs start to occur that seem to confirm it. So they start preparing for the baby in a very sweet and naive way. They might ask for advice from Hagrid on how to take care of magical creatures (thinking the baby will be like a magical creature in some ways) and from Hermione on how to study up on child - rearing in the wizarding world.
Yes, there are likely some fanfictions that handle this concept in a non - adult way. Some might explore it from a magical or alternate - universe perspective where the pregnancies are part of a more family - friendly adventure or a different take on the relationships in the Harry Potter universe. However, you need to be careful when searching for such fanfictions as there could be a mix of appropriate and inappropriate content.
Well, if we were to consider a non - inappropriate version, a possible plot twist could be a time - travel scenario. Maybe Naruto travels back in time and, instead of a romantic or sexual relationship, he ends up being in a situation where he has to protect Mikoto from some great danger. And through some magical or ninja - like means, something happens that gives the false appearance of pregnancy as part of a plot by an enemy to create chaos. So Naruto has to clear his name and also save Mikoto from the real threat.
A plot twist could be that Karin's pregnancy is a false alarm, but in the process of believing it was real, Naruto and Karin realize their true feelings for each other. They might have been in denial before, but this situation forces them to confront their emotions and they end up starting a real relationship.
One possible plot twist could be that the girl who is pregnant has some sort of magical ability related to the pregnancy that no one expected. Maybe she can communicate with the unborn child in a magical way. Another could be that Harry discovers he's not the real father, but due to some magical mix - up, he has to take on the role anyway.
One possible plot twist could be that the pregnancy is part of a larger scheme by a third party. Maybe Voldemort or some other dark wizard has manipulated the situation to either gain control over Lucius or to use Harry's unborn child for some dark purpose.
One possible plotline could be centered around the friendship aspect. Harry, Hermione, and Ginny might be worried about how their friendship will be affected by the pregnancies. They could work together to ensure that they still support each other through the changes. Another could be about how the wizarding community reacts. Maybe there are some old - fashioned views that they have to deal with, but they prove everyone wrong by handling the situation gracefully.
One possible plot development could be the initial shock and confusion for both Harry and Hermione. They would have to deal with the reactions of their friends, like Ron, who might be very surprised or even a bit jealous. Then they'd need to figure out how to balance their new situation with their fight against Voldemort or other magical threats. Another aspect could be how they prepare for the baby, from finding a safe place to live to getting all the necessary baby supplies in the wizarding world.