A Natsu x Lucy pregnant fanfic could be full of heartwarming moments. Think about Natsu being overprotective of Lucy during her pregnancy. He'd probably be a bit clumsy at first, but his love for her would shine through. And Lucy would be the one trying to keep things in order while also dealing with her hormonal changes. It could also add a new dynamic to the Fairy Tail group as a whole.
One possible plot could be about the challenges they face as new parents. Maybe they have to balance their work with taking care of the baby. Gru, with his past of being a villain, might be worried about how his past could affect their child. Lucy, on the other hand, could be using her skills from the Anti - Villain League to keep the family safe. They might also have funny moments like when the Minions try to help with the baby but end up causing chaos.
One plot idea could be that a magic spell goes wrong and Lucy ends up pregnant. Natsu is initially shocked but then quickly embraces the idea of being a father. They then have to deal with the guild's reactions, some of which are positive and some negative.
It's highly likely that there exists a fanfic with a Nalu and Lucy pregnancy plot. Given the large number of fanfic writers and the popularity of the Nalu ship, many fans like to create alternate storylines for the characters. Some might be interested in exploring the idea of Lucy becoming pregnant, perhaps dealing with how Natsu and Lucy would handle the situation, their reactions, and how it would affect their relationship and the world of Fairy Tail around them.
Their relationship would likely become stronger. Having a baby together means they have a new bond that ties them even closer. They would have to rely on each other more, for example, when taking turns to take care of the baby at night.
Well, FanFiction.net is a great place to start. It has a vast collection of fanfics from various fandoms, including Fairy Tail. Another option is AO3. These platforms have tagging systems. So, look for tags related to Nalu, Lucy, and pregnancy. But keep in mind that not all fanfics may be well - written or to your taste, so you might have to sift through a few to find the one you like.
Their friends would likely be shocked at first. Happy for them, but also a bit worried. Erza, for example, would probably be very protective. She might start giving Lucy all sorts of advice on staying healthy and safe during the pregnancy. Gray might be a bit awkward around the whole situation at first, but would eventually warm up and offer his support in his own way, like helping Natsu with any odd jobs or tasks so he can focus on Lucy.
First, focus on Lucy's emotions. Since she's pregnant, she'll have a whole range of feelings like joy, fear, and anticipation. Show how these emotions influence her actions and decisions. For example, she might be more cautious about going on missions. Second, develop the relationships around her. How do her friends and family react? Their reactions can also drive the story. Third, give her a goal related to the pregnancy, like ensuring a safe future for her child, and let her character grow as she tries to achieve that goal.
One idea could be exploring how Lucy's pregnancy affects her magic. Maybe she discovers new powers or has to adapt her existing ones. Another plot could focus on the reactions of her friends in the guild. They might be overjoyed and very protective. Also, a story could be written about how she prepares for the baby's arrival while still dealing with any threats to the guild or the magical world.
You can start by looking on Archive of Our Own (AO3). It has a large collection of fanfics from various fandoms. Just type in 'Laxus x Lucy pregnant' in the search bar and see what comes up. Another option is FanFiction.net, which also has a wide range of Fairy Tail fanfics.