A great plot could be Klaus and the reader trying to find a safe haven for their unborn child. They might travel to different places, encountering various supernatural beings along the way. Some might offer help, while others might see the baby as a threat. Also, the internal conflict within Klaus about being a father, considering his own troubled past, could be a central part of the story.
Well, a plot could revolve around Hope having visions of Klaus's future. In these visions, she sees that he's in great danger from an ancient evil that is about to be unleashed. So, she sets out on a journey to find a way to prevent this from happening. Along the way, they have to face their own personal demons as well. Maybe Hope has to come to terms with her anger towards Klaus for not being there for her all the time. Another plot could be that Klaus is cursed and Hope is the only one who can break the curse, but it comes at a great cost to her powers.
One popular Klaus Mikaelson pregnant fanfiction might involve a unique plot where the pregnancy is a result of a magical spell gone wrong. This could lead to all sorts of chaos and drama within the supernatural world he inhabits. Maybe other characters are forced to protect the pregnant Klaus due to the implications it has on the balance of power.
One plot idea could be Kai and Klaus teaming up to take on a common enemy. Maybe a powerful witch or vampire that threatens their families or their own existence. They could start off as reluctant allies, but over time develop a grudging respect for each other.
One interesting plot could be the struggle of the OC to fit into the Mikaelson family while being pregnant. She might face challenges from the family's complex dynamics and their vampire - werewolf heritage. For example, there could be concerns about the nature of the baby, whether it will inherit supernatural abilities and how to protect it from the family's enemies.
Maybe Harry discovers his Mikaelson heritage when strange things start to happen to him during his time at Hogwarts. His newfound powers could attract the attention of both the wizarding world and the supernatural world from Klaus' side, leading to a complex web of alliances and rivalries. He might have to learn how to balance his wizarding skills with his vampire - like abilities.
Perhaps there could be a situation where a dark magic spell in the Potter universe somehow links to the Original vampire's curse in Klaus's world. Harry and Klaus are forced to work together to break the spell/curse. Along the way, Klaus sees a bit of himself in Harry's determination and Harry realizes that Klaus isn't entirely a monster.
One idea could be that Elijah discovers he is going to be a father during a time of great turmoil in the supernatural world. His family's enemies might see this as a weakness and target him and his unborn child. Another plot could involve Elijah trying to protect the mother of his child from the dangerous vampire politics and ancient curses that could harm her or the baby. Maybe he has to make a deal with a powerful witch to ensure a safe pregnancy for the mother.
One idea could be that Hope discovers she's pregnant during a time of great turmoil in the supernatural world. She has to hide her pregnancy to protect her unborn child from those who might want to use it for their own gain. Maybe she goes into hiding with a trusted friend or family member.
One idea could be that Elena discovers she's pregnant and tries to keep it a secret from Klaus at first. But as the pregnancy progresses, she realizes she needs his help. Another could be that Klaus is initially angry but then becomes protective. Maybe there are threats from other supernatural beings because of the baby's unique heritage.
One idea could be that they face opposition from their respective families or vampire/werewolf communities. Their pregnancy might be seen as a threat to the status quo or an abomination in the eyes of some. Another plot could involve them trying to find a safe place to raise their child, away from all the danger and politics. Maybe they go into hiding in a remote location and have to learn to live a normal life while also dealing with the challenges of Caroline's pregnancy as a vampire.