Rose could try to manipulate Cal as well. Since she knows how much he cares about his reputation, she might threaten to expose some of his secrets if he doesn't leave her alone. This way, she can protect herself and her unborn child from his possible harmful actions.
Rose might stand up to Cal bravely. She could tell him that she will not let him control her life anymore, especially now that she has a child to think about. She would be defiant and make it clear that she wants nothing to do with him.
One possible plot development could be that Cal tries to use Rose's pregnancy to his advantage. He might try to claim the baby as his own to save face in society, even though it's not. This could lead to a huge struggle between Rose and Cal as she tries to break free from his control and protect her unborn child.
One common theme is redemption. Since Cal was initially portrayed as a rather unlikable character in the movie, many fanfics focus on his journey to redeem himself in Rose's eyes. Another theme is the exploration of their relationship, how they might have overcome their differences. For example, their different social classes.
In some fanfictions, when Cal and Mare are pregnant, it's often portrayed with a great deal of emotion. The writers might focus on how they adjust to the new situation. For example, Cal could be shown as being overly protective, while Mare might struggle with the idea of being more vulnerable due to her pregnancy. It can also be a source of drama, like how they deal with the political implications in the world they live in. Their relationship might grow stronger as they face this new chapter together, or it could be a source of conflict if they have different views on how to raise the child in a world full of strife.
A really interesting Cal and Rose fanfic I came across was 'Cal's Redemption'. In this story, Cal tries to make up for his past mistakes and win Rose back. It delves deep into his character, showing his transformation from a somewhat villainous figure to someone who is truly worthy of Rose's love. It also has great descriptions of their interactions and the emotions that run between them.
The relationship would become more complex. There could be some disagreements about how to raise the baby. Cal, with his royal upbringing, might have different ideas compared to Mare, who grew up in a more humble setting. However, through these differences, they would grow together, understanding each other better and finding a middle ground to ensure the best for their baby.
I'm not sure if there is a specific fanfiction exactly with those elements. Fanfiction can cover a wide range of scenarios, but this seems rather inappropriate and not in line with the general respectful portrayal of the Titanic story. The Titanic story is often remembered for its tragic and romantic aspects in a more refined way.
Perhaps in the fanfiction, Rose is pregnant and the Titanic doesn't sink. When they reach their destination, they have to figure out how to build a life together with a baby on the way. They face challenges like finding a place to live and Jack finding a stable job. But their love for each other and the anticipation of the new life keep them going.
One possible storyline could be that Rose discovers she's pregnant after she and Jack's brief but passionate encounter on the ship. This could add a whole new layer of drama. Maybe she tries to keep it a secret at first, fearing the reaction of her mother and Cal. As the Titanic starts to face its doom, she's not only worried about her own survival but also that of her unborn child.
In this fanfiction, Rose being pregnant might lead to a situation where she has to fight for her rights to keep the child. Her family, who may not approve of her relationship with Jack, could try to take the baby away. So she has to prove that she can be a good mother on her own. She might also document her pregnancy journey in a diary, writing about her memories of Jack and how she hopes the baby will grow up with the same love for life that Jack had.
One common theme could be the anticipation and excitement about the upcoming birth. It might focus on how the characters, mare and cal, are preparing for the new arrival.