One popular storyline could be about how they navigate their new relationship while dealing with the pregnancy. Maybe they face challenges from family and friends who might not be fully supportive at first. Another could be them preparing for the baby, like decorating the nursery together. There could also be a storyline where Marinette's creative side is influenced by the pregnancy, and she creates new fashion designs inspired by the upcoming baby.
Fanfiction.net is also a great place to search. There are a lot of Miraculous Ladybug fanfictions on this site. You might need to use the search bar and type in relevant keywords like 'Marinette Luka pregnant' to narrow down the results. However, the quality can vary, so you'll need to read the summaries and reviews to find the good ones.
There's also 'The Luka - Marinette Connection'. In this fanfiction, the connection between Luka and Marinette is explored on a deeper level. It starts with Luka noticing Marinette's little quirks and how she tries to hide her feelings. As the story progresses, they start to open up to each other more. The author creates a really engaging story by adding in some mystery elements related to the Miraculous and how it might affect their relationship.
There are many interesting fanfictions about Marinette and Luka. Some might focus on their relationship development outside of the superhero chaos. For example, a fanfiction could explore how they go on a simple date, sharing their interests like Marinette's fashion design and Luka's music.
One possible aspect of this fanfiction could be exploring the relationships between Adrien, Marinette, and Luka. Maybe it's a story where their personalities merge in some magical or scientific way. For example, their combined traits could lead to a new superhero or a character with a very unique set of skills and emotions.
The theme of hidden identities also exists. Given the context of the Miraculous world they live in, sometimes their identities as heroes or normal teens are explored in relation to their relationship. It adds an extra layer of mystery and drama to the fanfiction, making it more engaging for the readers.
One possible plot could be that Luka has been mind - controlled by an akuma. In the Miraculous Ladybug universe, akumas often make people do things they wouldn't normally do. So, he kidnaps Marinette not out of his own will but because of the akuma's influence. Marinette might initially be shocked and scared, but then she could try to find a way to break the akuma's hold on Luka and save them both.
In Miraculous Ladybug fanfiction, Marinette and Luka often have a very sweet relationship. Luka is shown as a supportive character. He is someone who can sense Marinette's emotions quite well. In many fanfictions, he becomes a source of comfort for Marinette, especially when she is stressed about her superhero duties as Ladybug or her regular life problems like school and friendships.
It could also create some drama. Maybe Marinette still has feelings for Adrien, and the kiss with Luka makes her confused. This could lead to a complex love triangle - like situation where she has to figure out her true feelings.