Maybe they get caught when Jacob is sneaking into the Cullens' place to see Renesmee. As a result, there could be a big fight between the werewolves and the vampires. The two groups, which have a tenuous peace, might break out into conflict again. Renesmee would be caught in the middle, feeling guilty for causing such trouble between the two factions.
In some fanfictions, they might get caught because someone spies on them. Once caught, Renesmee could face a lot of restrictions on her freedom. Jacob might have to face the wrath of the Cullens. However, this could also be an opportunity for them to finally be open about their relationship. They could start a dialogue with the people around them to try and gain acceptance, but it would be a difficult and long process.
In fanfiction, if they're caught, it could be the start of a whole new adventure. Their relationship has always been a bit of a taboo in the Twilight universe. So being caught might force them to re - evaluate their relationship. They might have to find a way to convince others that their love is real and worth fighting for. This could involve them going on a journey to prove themselves, facing various challenges along the way, and ultimately changing the way the vampire and werewolf communities view their relationship.
One possible reason could be that Renesmee simply has different interests. Maybe she is more drawn to a different lifestyle or set of values that Jacob doesn't align with. For example, she might be interested in exploring the world in a more solitary way while Jacob is more about the pack and community.
Another theme is growth. As they are both young in the story, fanfictions often show how they grow both individually and as a couple. For example, they might learn how to deal with their unique powers and how that affects their relationship.
A popular one is 'Jacob and Renesmee: A New Beginning'. In this fanfiction, the author focuses on the idea of Jacob and Renesmee starting a new chapter together. It has some really sweet moments where Jacob is protective of Renesmee and they both discover new aspects of their relationship. It's a heartwarming take on their potential future.
One great Jacob Black and Renesmee fanfiction is 'Forever Bonded'. It beautifully explores their relationship as Renesmee grows up. The author does a wonderful job of showing how Jacob's loyalty and Renesmee's unique nature interact. Another good one is 'Renesmee's Protector'. It focuses on Jacob's role in protecting Renesmee from various threats. And 'The Unbreakable Link' is also worth reading, which delves deep into the emotional connection between them.
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.
Yes, there are likely fanfictions out there about this concept. The 'Twilight' series has a large and creative fan base. However, such fanfictions may deviate significantly from the original story. Some might explore how Jacob and Renesmee's relationship could develop in this new situation, while others could focus on the implications for the 'Twilight' world as a whole.
Another reason could be to protect her from a prophecy. In the world of fanfiction, there could be a prophecy that foretells Renesmee's doom if she stays with the Cullens. So Jacob, thinking he's doing the right thing, kidnaps her to keep her away from that fate.
They are a popular couple in fanfiction because their relationship in the original Twilight series is quite complex and full of potential. Their age - difference - like situation (Jacob being older in a way) and the fact that Renesmee is a half - vampire half - human make for an interesting dynamic that fanfiction writers love to explore.
One great 'Jacob and Renesmee fanfiction' is 'The Unlikely Bond'. It beautifully explores their relationship as Renesmee grows up. Another is 'Jacob's New Role' which delves into how Jacob adjusts to being part of Renesmee's life in a more complex way. And 'Renesmee's Choice' is also interesting as it shows Renesmee making decisions that impact their relationship.