In the fanfiction where Lucy tells Natsu she's pregnant, how does Natsu react?

Well, Natsu is a passionate character. He could react with a lot of excitement. He might pick Lucy up and spin her around, laughing and saying how amazing this is. Or, he could also get a bit worried and start asking Lucy all sorts of questions about her health and what they need to do next.

Erza would probably be very protective. She would make sure Lucy has everything she needs and would be strict about her safety. Gray might be a bit awkward at first, but then he'd be supportive. Happy would be over the moon. He'd constantly be around Lucy, bringing her fish and trying to cheer her up. Wendy would be excited and would offer to use her healing magic to check on the baby's health regularly.

Natsu would likely be extremely guilty. He might immediately stop whatever he was doing and rush to Lucy's side.

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.

The plot could develop with them preparing for the baby. They might start looking for a bigger place to live. Natsu could go on quests to earn more money for the baby's needs.

Lucy might be heartbroken. After all, Team Natsu was like a family to her. She could initially go into a state of shock and disbelief. Maybe she would try to plead with the team to let her back in, explaining that whatever they thought she did was a misunderstanding.

Well, they are adventurers. So their lifestyle is quite active and full of risks. Now that Lucy is pregnant, they have to change that. Natsu might have to be more careful about his battles, and Lucy might not be able to go on as many adventures. And there's also the social aspect. How will their friends and the guild react? Some might be happy, but others might worry about how this will affect the team. And of course, there are the normal pregnancy challenges like making sure Lucy is healthy and getting proper medical care.

His friends would be very concerned. Gray, for example, might try to physically stop Natsu from drinking more. Erza would likely be more gentle and try to talk to him, to make him understand that getting drunk won't bring Lucy back.

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.

She might start to blush furiously. Given her character, she is a bit shy when it comes to romantic matters. And then she might start to stammer out a response, not really sure what to say at first. As she composes herself, she could tell Natsu that she has feelings for him too but in a very gentle and sincere way.