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.
I'm not sure if there is a specific fanfic with that exact plot. There are a vast number of fanfics out there in the Fairy Tail fandom, but it would take some searching through various fanfic platforms to know for sure. Some popular fanfic sites like Archive of Our Own or FanFiction.net might be good places to start looking if you're interested in such a story.
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.
First, you need to develop Lucy's character. Think about her personality traits, like if she's usually calm or a bit of a worrier. Then, plan out the plot. You could start with how she discovers she's pregnant. Maybe it's a surprise or something she's been hoping for.
Gray could also be a possibility. He and Lucy have a friendly rivalry and there are moments where their relationship could be interpreted as having deeper feelings. It would be an interesting twist if Gray was the father, as it would change the dynamics between him, Natsu, and Lucy in the fanfic.
In some 'lucy pregnant fanfic', the story could revolve around Lucy's pregnancy dreams and aspirations for the future of her child. It might include her preparing a nursery, thinking about the baby's education, and how she plans to be a great mother.
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.
Gru was shocked when he learned that Lucy was pregnant. He paced back and forth, his mind racing with thoughts of how their lives would change. He was both scared and excited. At first, he worried about whether he could be a good father, but then he looked at Lucy's glowing face and knew he would do anything for their family.