Their relationship would likely become more intimate and protective. If Abby is pregnant, McGee would be constantly looking out for her, making sure she's not overworking or getting into dangerous situations at work.
There could be many scenarios in such a fanfiction. Maybe it happens during a high - stress case when they finally realize their feelings for each other. For example, after they solve a really tough mystery together and the relief and joy make them share a spontaneous kiss.
One possible plot could be that Abby discovers she's pregnant. McGee would be over the moon but also a bit nervous. They might face challenges at work as they try to balance their jobs at NCIS with the upcoming new addition to their family. Their colleagues could be supportive, but there might also be some concerns about Abby's safety in the field.
It could also lead to some complications. For instance, if there are any rules in the NCIS about relationships between colleagues. They might have to face some disciplinary actions or at least some serious discussions with their superiors. But in the end, their love could overcome these obstacles as they fight for their relationship together.
Abby's character might become more domesticated. She's always been a bit of a free spirit, but being married could make her more settled. She might start to focus more on building a home and a family life. For McGee, he could become more confident in his personal life. He's often been a bit shy and reserved, but with Abby by his side as his wife, he might find himself being more assertive in social situations. Also, they could both develop more patience with each other as they face the daily challenges of married life.
A plot twist might be that Abby discovers she's pregnant before the wedding, but she's not sure if McGee is ready for fatherhood. This could create a rift between them as they struggle to communicate their feelings. Or, it could turn out that someone has been secretly trying to break them up all along, and at the last minute, they reveal all the lies and misunderstandings they've been spreading. Also, there could be a situation where McGee has an accident and loses his memory, forgetting about the wedding and his relationship with Abby, leading to a heart - wrenching journey of her trying to make him remember.
A fellow scientist named Tom, perhaps. He could be a bit of a joker but also very brilliant. He and Abby might have a friendly rivalry, constantly trying to outdo each other in their experiments, but also respecting each other's skills. And then there could be the lab technician, Lisa. She is the one who keeps all the equipment in working order. Without her, Abby's experiments would be constantly interrupted by faulty machinery. She's a bit quiet but very reliable.
One possible storyline could be that Gibbs discovers Abby is pregnant and becomes extremely protective. He might start hovering around her at work, making sure she's not overexerting herself. This could lead to some comical moments as Abby is a very independent character and might not take too kindly to Gibbs' over - protectiveness at first.
There are fanfics where Abby's pregnancy is a big surprise to everyone, including herself. In these stories, her relationship with the baby's father (whichever character the author chooses) can be explored in depth. It could be a story full of drama, with Abby trying to figure out how to balance her new life as a soon - to - be - mother and her important role in the NCIS team.
Their relationship would likely become more intimate on an emotional level. Gibbs would probably be more open and tender towards Abby, seeing her in a new light as a mother - to - be.