Even though Mon - El leaves, their relationship can still develop. Kara could keep a journal for the baby, writing about her feelings for Mon - El. When Mon - El returns (if he does), he could read it and realize how much Kara truly loved him. Also, Kara might have dreams or visions of Mon - El during her pregnancy, which could show that their connection is still strong on an emotional level.
The relationship could develop in a very bittersweet way. Kara, while pregnant, could start to understand Mon - El's reasons for leaving better as time passes. She might send him messages (even if he doesn't receive them right away) about the baby's development, showing that she still wants him to be part of their lives. Mon - El, on his journey away, could be constantly thinking about Kara and the baby, and when they eventually cross paths again, their relationship could be more mature and understanding, based on all the time they spent apart.
They would become more united. Having a baby together would make them a family, and they would have a stronger bond as they face the challenges of raising a child. Their relationship would be more about teamwork, not just as superheroes but also as parents.
She might initially be heartbroken. Kara, being strong - willed, could focus on taking care of herself and the unborn child. She may turn to her friends at the DEO for support, like Alex, who would be there to help her through the difficult time both emotionally and physically.
He might leave to protect Kara and the unborn child. Maybe he discovers that there is some kind of danger following him that could put them in jeopardy, so he decides to sacrifice his time with them to keep them safe.
You can try Archive of Our Own (AO3). It has a vast collection of fanfictions, and there are likely to be many about Kara and Mon - El being pregnant. Just use the search function and type in the relevant keywords.
Love is a very common theme. Since their relationship is a central part of the stories, it often explores different aspects of love like first love, unrequited love, or love that overcomes obstacles.
One popular Kara and Mon - El pregnant fanfiction might be 'A New Beginning'. It focuses on how they navigate their relationship while expecting a child. It shows Kara's struggle between her superhero duties and impending motherhood in a really interesting way.
Their relationship would likely become more protective. Mon - El would be constantly worried about Kara's well - being and that of the baby. He would be more vigilant and might even become overprotective at times. Kara, on the other hand, might struggle with accepting too much help as she is used to being the one who protects others. But she would also have to learn to rely on Mon - El more, which could strengthen their bond in a new way.
In this fanfiction scenario, Kara being pregnant and Mon - El leaving could lead to a complex story. Maybe Mon - El leaves because he fears for Kara's safety due to her pregnancy and his past or some external threats. Kara is left heartbroken and pregnant. She may initially be in denial about Mon - El's departure, but then has to face reality. As she goes through the pregnancy, she could meet new people who help her, like other superheroes or just kind - hearted civilians. And throughout the story, there could be a lingering hope that Mon - El will return, but also a growing sense of self - reliance in Kara as she prepares to be a mother alone.
Fanfiction.net is also a good place. There are many writers who post their 'kara and mon el' related fanfictions there. Just make sure to use the right keywords in the search to narrow down to the ones with their kiss.
There's a 'kara and mon el fanfiction' called 'Destined Hearts'. In this one, the story takes an interesting turn as it explores their relationship in the face of new threats in the city. It has a lot of action - packed scenes intertwined with their growing affection for each other. This fanfiction really keeps you on the edge of your seat.