There might be some extremely niche fanfiction out there with this concept, but it goes against the established lore of the 'Twilight' universe in many ways. Vampires in the 'Twilight' world are undead and have different biological functions compared to humans, and werewolves also have their own unique biology. So while fanfiction can be creative, this would be a very out - of - the - box and perhaps not very common plot.
Bella would probably be extremely shocked. She has deep relationships with both Jacob and Edward. She might feel a mix of jealousy, confusion, and concern for what this strange situation means for their relationships. Carlisle, being the rational and kind doctor, would be very confused at first but would likely try to find a scientific or magical explanation for this seemingly impossible event.
Well, if we consider the fanfiction world, it could be due to some new and unique genetic or magical alteration. Perhaps there was an experiment by a powerful and mad scientist in the Twilight realm that messed with their biological makeup. But it's really a wild departure from the original Twilight lore where vampires are undead and not supposed to be able to get pregnant in the normal way, and werewolves have their own set of biological norms.
It would be a very strange and unique take. Given their different natures in the 'Twilight' world, it would require a lot of creative liberties. Maybe it could involve some sort of magic or supernatural force that overrides their normal biological limitations. But overall, it would be a very different kind of story from the original series.
In Twilight fanfiction, Edward is often depicted as the brooding, vampire hero. He's complex, with his struggle between his love for Bella and his vampire nature. Jacob, on the other hand, is the warm - hearted werewolf. Fanfictions might explore their relationship in different ways. Sometimes they are rivals, fiercely competing for Bella's love. In other stories, they might find a way to coexist or even become friends, despite their natural enmity in the original series.
There's also 'Twilight Reimagined: Edward and Jacob'. In this one, the author completely reimagines the story. Edward and Jacob are forced to work together in a world where the Volturi are more powerful than ever. It has a lot of great character development and the plot twists keep you on your toes.
One popular trope is the 'rivalry turned friendship'. In many fanfictions, Edward and Jacob start off as bitter rivals for Bella's affection. But as the story progresses, they realize they have more in common than they thought. Another trope is the 'alternate universe' where their roles are reversed. For example, Edward could be a werewolf and Jacob a vampire. It's a fun way to play with the established characters.
I'm not sure if there is a specific 'Jacob gets Renesmee pregnant' fanfiction. Fanfiction can cover a vast range of ideas, but this is a rather controversial and unusual plot. It might exist in some corners of the fanfiction world, but it also goes against some of the original concepts in the source material. You would need to search through various fanfiction platforms like Archive of Our Own or FanFiction.net to find out for sure.
One common plotline is a love triangle where the female character, often Bella, is torn between Edward and Jacob. The fanfiction might explore different outcomes of this triangle, like her choosing Jacob instead of Edward which is a big deviation from the original story.
Well, a lot of Jacob Edward Twilight fanfiction delves into the idea of them finding common ground. In some stories, they end up becoming friends despite their initial rivalry over Bella. There are fanfictions where they have to team up against a new threat in the vampire - werewolf world that is even more powerful than the Volturi. These stories often play with the characters' personalities and expand on the lore of the Twilight universe.