Another possible antagonist could be a new, unknown enemy who is interested in Saiyan genetics. Since Bulma is carrying a Saiyan - human hybrid, this new foe could try to kidnap her to study the fetus. This would force Vegeta to go on a rescue mission while also protecting Bulma from harm.
Frieza or his remnants could be antagonists. They might see the unborn child as a potential threat in the future, especially if it has strong Saiyan powers. So they could plan to attack Bulma to prevent the birth.
There could be a rogue Saiyan who has different ideals from Vegeta. This Saiyan might think that the baby should be raised in a more traditional, warrior - like way and try to take the baby from Bulma and Vegeta. Or, an evil scientist who wants to experiment on the baby's unique Saiyan - human DNA could be the main antagonist, creating all kinds of challenges for Vegeta and Bulma to protect their child.
The fanfiction could focus on the challenges they face during the pregnancy. For example, Bulma might have some health scares that make Vegeta worry a great deal. He could struggle with his emotions, not knowing how to handle his fear of losing her or the baby. Also, there could be a sub - plot about how the news of Bulma's pregnancy affects the political situation in the Dragon Ball universe. Some enemies might see it as an opportunity to attack while some allies might offer more support than ever.
Also, Dr. Briefs, Bulma's father, could be in the story. He might be helping Bulma with any scientific aspects related to her pregnancy, or just being a supportive father figure during this time. And perhaps some of the other Z - Fighters could make appearances and have their own reactions to the news of Bulma's pregnancy.
Perhaps it could be the school bully. This bully might be jealous of Vegeta's strength and popularity among some students, and also of Bulma's intelligence and charm. So, he tries to create problems between them, like spreading false rumors or trying to sabotage their school projects.
Sometimes new, original antagonists are created for dark fanfiction. They could be powerful demons or shadowy figures from Vegeta's past on Planet Vegeta. These antagonists might have vendettas against Vegeta and see harming Bulma as a way to get revenge. They can bring in elements of mystery and horror to the story.
In a 'Vegeta gets Bulma pregnant fanfiction', perhaps it starts with a big event that makes Vegeta realize how much he values Bulma. This leads to them becoming closer and soon Bulma is pregnant. The story could then focus on how Vegeta's Saiyan pride affects his reaction. He might be initially shocked but then become super protective. And Bulma, being the smart and strong - willed woman she is, would be preparing for the baby while also dealing with Vegeta's sometimes over - the - top reactions.
A third fanfiction concept could be about how they prepare for the baby's arrival. Vegeta, not knowing much about Earthling baby things, has to learn. Bulma tries to teach him, and there are a lot of cultural clashes and misunderstandings at first. But as time goes on, they work together to create a perfect nursery and get ready for their new family member.
Well, Vegeta himself could be seen as the antagonist in the beginning. Since he is the one doing the kidnapping, he's causing distress to Bulma. However, as the story progresses, the real antagonist could turn out to be someone else. For example, another alien race that is after Vegeta and uses Bulma as bait to lure him into a trap. So, it's not so straightforward in a fanfiction.
Their relationship would likely become more intimate and committed. With a baby on the way, Vegeta would probably be more protective of Bulma. He might show his love in more practical ways, like making sure she has everything she needs.
The main characters would obviously be Vegeta and Bulma. Vegeta is the Saiyan prince, a powerful and often brooding character. His presence brings a sense of strength and an otherworldly quality to the story. Bulma, on the other hand, is a human, a brilliant scientist. She's strong - willed and independent, which makes for an interesting dynamic when paired with Vegeta, especially during her pregnancy.