Zabuza would probably be initially shocked. He might see it as a complication to their plans, but as time goes on, he could become protective. Naruto, being the kind - hearted person he is, would likely offer his support and friendship. He might not fully understand Haku's situation at first, but he would try to be there for her.
The villagers would have a mixed reaction. Some might be superstitious and think it's a bad omen that Naruto, a male, is pregnant and has time - traveled. Others, especially those who know Naruto well, would be more accepting. They would see it as just another one of Naruto's strange but ultimately positive adventures. And Naruto's friends like Shikamaru would be initially dumbfounded but then start thinking of strategies to deal with the situation and how to use it to their advantage.
I'm not sure if there's a specific and widely - known 'Naruto x Haku pregnant fanfiction'. But it's very likely to exist given the creativity of fanfiction writers. They often take existing characters and put them in unexpected situations. A story about Haku being pregnant could involve all kinds of new plotlines, like dealing with the reactions of other characters in the Naruto world, or how Haku would handle the physical and emotional changes. It might also be a way to introduce new elements to the Naruto universe that were not present in the original series.
Sasuke would be deeply affected. He and Naruto had a complex relationship. He might feel regret for not being there to help Naruto and also feel a new sense of purpose in avenging his friend. Sakura would be heartbroken. She had always cared for Naruto, and his death would make her question the purpose of the ninja life. Haku herself would be in a state of shock and disbelief. She would feel a heavy burden of guilt, knowing that Naruto sacrificed his life for her. She might become more withdrawn initially but then use Naruto's memory as a motivation to become stronger.
Sasuke might be more understanding. Given his own experiences of leaving Konoha, he could respect Naruto's decision. However, he might also secretly plan to keep an eye on Naruto from afar to make sure he is safe.
Spock would likely be very logical yet also show deep concern. He might start researching Vulcan and human pregnancy traditions to better support Uhura. Kirk would probably be excited and offer his full support, making sure Uhura has all the resources she needs. The rest of the crew, like Bones, would be more medically focused, constantly checking on her health.
Hiro would probably be a bit awkward at first but then really excited. He'd see it as a new addition to their 'family'. Baymax would be very practical, constantly monitoring her health and giving advice on proper prenatal care. GoGo might be initially surprised but would quickly become supportive, like a tough - love sister. Fred would likely make a lot of jokes about it at first but then also be there for her. Tadashi's memory could be a source of inspiration for them all to support Honey Lemon during this time.
Natsu might be really confused and sad at first. He's used to having Lucy around for adventures. But he would probably respect her decision in the end, knowing it's for the baby.
Sasuke might be initially dismissive but secretly concerned. He would probably keep an eye on Naruto from a distance, not wanting to show too much emotion. Sakura, on the other hand, would be more openly worried and would try to use her medical skills to figure out if there's something physically wrong with Naruto.
The Akatsuki members, if they were to encounter Naruto in this state, would have different reactions. Some might see it as an opportunity to target him when he's vulnerable. However, others like Pain, who has his own beliefs about the cycle of pain and suffering, might be a bit more conflicted. He might see Naruto's unborn child as a symbol of a new beginning or just another target. And the other Konoha ninjas, especially the younger ones, would look up to Naruto even more. His pregnancy and time travel situation would make him seem even more of an enigma and a source of inspiration as he's facing such unique challenges.
Naruto would be over the moon. He's always been a family - oriented person deep down. He'd probably start blabbing to all his friends about how amazing Hinata is and how excited he is to be a father.