In the fanfic, the pregnancy could be the catalyst for them to truly open up to each other. They might share their deepest fears and desires. Klaus could reveal his insecurities about being a father, fearing he'll be like his own father. Caroline could comfort him and they could bond over their hopes for the baby. As the pregnancy progresses, their love could grow stronger, and they could become a more united front against any threats.
In such a fanfic, there could be a lot of drama. Maybe Klaus would become extremely protective of Caroline. He might try to keep her safe from all the threats in their supernatural world, like his enemies who could use her pregnancy against him.
Klaus would be very attentive to Caroline's pregnancy cravings. He'd see it as his duty to take care of her during this time. He might cook for her himself if he can, or take her to the best restaurants to get what she wants. He would be a bit overprotective too, making sure that whatever she eats is of the highest quality and safe for her and the baby. He'd also listen intently to her when she talks about her cravings, finding it endearing and a sign of the new life growing inside her.
Klaus might be overjoyed. He has always been attracted to Caroline, and having a baby with her could be the ultimate sign of their connection. He would probably be very protective, using all his power and resources to keep her and the unborn baby safe.
Their relationship could become more intimate as they bond over the baby. They might start to see each other in a new light, with Klaus showing a more tender side and Caroline learning to trust him more deeply.
It could become more intense. They now have a shared responsibility, so they might be more connected. Klaus might be more tender towards Caroline, and Caroline might start to see Klaus in a different light, perhaps more as a partner rather than just an acquaintance.
There are various takes on how such a pregnancy would occur in fanfiction. Some might involve magic or some unique supernatural event. These stories often delve into how the characters, especially Caroline who is a strong - willed character, deal with the unexpected situation of pregnancy. It's a fascinating exploration of their characters beyond what we see in the original show.
Klaus may be overjoyed. Given his complex character, he might see this as a new beginning, a chance to create a family of his own in a way he never thought possible. He could immediately start making plans to ensure Caroline and the baby are well - cared - for.