Well, one possible plot could be that Natsu and Lucy's relationship evolves from friendship to something more romantic. Then, an unexpected pregnancy occurs which throws their lives into chaos. They might have to face the reactions of their friends and deal with their own fears and insecurities about becoming parents.
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.
Well, a plot could involve Natsu and Lucy trying to keep the pregnancy a secret at first. They don't want to cause a stir in the guild right away. As the pregnancy progresses, they start to realize they need to prepare. Natsu tries to earn extra money by taking on dangerous jobs, which Lucy doesn't like. Meanwhile, the baby could have some sort of special magic that starts to show even before it's born, attracting the wrong kind of attention from dark mages.
It could be that Natsu is part of an experiment in a parallel universe within the fanfiction. The experiment gives him the ability to get pregnant. His journey would involve coming to terms with this new state, facing the challenges of pregnancy, and maybe even finding a way to reverse it if he wishes.
Perhaps a plot twist could be that Lucy discovers she's pregnant but Natsu has lost his memory. He doesn't remember their relationship and is confused by the news. This would create a lot of emotional turmoil for Lucy as she tries to make Natsu remember while also dealing with the physical and mental changes of pregnancy.
Well, one possible plot could be that Lucy has to face the challenges of pregnancy alone after Natsu leaves. She might struggle with financial difficulties and the emotional turmoil of raising a child without the father. She could then find support in her friends in the guild, who help her through the tough times and she eventually becomes a strong, independent mother.
Well, it could completely change the dynamic of their relationship. Firstly, they would have to deal with the responsibilities of impending parenthood. Natsu, being his impulsive self, might have to become more responsible. Lucy, on the other hand, would probably be more cautious about her actions as she has a life growing inside her. This event could also change their relationships with their friends in the guild. Their friends would likely rally around them, but there could also be some who might be shocked or even a bit envious. It could also lead to new story arcs, like how they prepare for the baby, finding a safe place to raise it, and what kind of parents they would be.
The guild master would likely have a very fatherly or motherly reaction. They would ensure that Natsu and Lucy have all the resources they need. Mirajane would be overjoyed and would start planning all kinds of things for the baby. Elfman might see it as a sign of Natsu becoming a real man and offer to train the baby when it grows up. However, there could also be some characters who are jealous or feel left out. For example, someone who has a secret crush on either Natsu or Lucy might be a bit bitter at first but would eventually come around to support them.
Some fans would be really excited. They might love the idea of seeing their favorite characters in a more mature and family - oriented situation. It could add a new dimension to the Natsu - Lucy relationship that they've always wanted to see.
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.
Well, it could start with Gray and Lucy being on a really dangerous mission together. In the midst of all the chaos and life - threatening situations, their emotions run high and they end up getting closer than they ever thought. Later, Lucy discovers she's pregnant. Gray then has to step up and be more responsible. They might face challenges like financial difficulties as they prepare for the baby. And there could be a sub - plot where they search for a safe place to raise their child away from the constant danger of their guild life.