In some Bellarke fanfictions, Finn might hurt Clarke emotionally. For example, if he shows more interest in another character, Clarke could feel betrayed and heartbroken. This could lead to her doubting their relationship and feeling a deep sense of loss.
One consequence could be that Clarke distances herself from Finn. She might become more closed - off and less trusting. This could change the dynamic of their relationship and make it difficult for them to work together, which is crucial in the survival - based world of Bellarke.
The plot might involve Clarke already having the pet when Bellarke stumbles upon her in the woods. The pet could be injured, and Bellarke helps Clarke take care of it. As they work together, they start to develop deeper feelings for each other. And the pet becomes a sort of symbol of their growing bond, while they also face challenges in the woods like finding food and shelter for all of them.
One great 'Bellarke, Clarke pregnant' fanfiction is 'A New Beginning'. It beautifully explores how Bellamy and Clarke deal with the pregnancy in the midst of their post - apocalyptic world. The author does a wonderful job of showing their emotions and the challenges they face.
Clarke would likely see the pet as a new responsibility. She'd start making plans for its care right away. Bellarke might be a bit more hesitant. He might think about the practicalities like how they're going to feed it. However, as he sees how much the pet means to Clarke, he'll gradually warm up to it. And eventually, they'd both be really attached to the pet, and it would become an important part of their relationship in the woods.
One great Bellarke Clarke Hurt fanfiction is 'Fractured Hearts'. It really delves into Clarke's emotional pain and how Bellamy tries to help her through it. The author does an amazing job of portraying Clarke's vulnerability and Bellamy's determination to be there for her.
One possible scenario is that she's trying to protect the Candy Kingdom from a new threat and Finn's impulsive actions get in the way. So, in her attempt to stop him from endangering the kingdom, she might accidentally hurt him. Another could be that she's under the influence of some sort of mind - controlling substance or magic and she ends up harming Finn without realizing it.
Well, the world of fanfic is vast. While I can't confirm the existence of a 'clarke kills finn fanfic' specifically, it's entirely possible. If it's a concept that someone has thought of, chances are there's a writer out there who has turned it into a fanfic. You could also ask in relevant fan communities or on social media platforms dedicated to the show to see if anyone knows of such a fic.
You can try Archive of Our Own (AO3). It has a vast collection of fanfictions, including many Bellarke ones where Clarke is hurt. Just use the search function and type in 'Bellarke Clarke Hurt' and you'll get a bunch of results.
One common theme is hope. The pregnancy often represents a new beginning and a glimmer of hope in their otherwise difficult world. For example, in many fanfictions, the group sees the baby as a sign that things can get better.