Well, a plot twist might be that Regina's pregnancy is a false one, created by an illusion spell. This could be part of a larger scheme to make her look vulnerable and draw out her enemies. Or perhaps the baby she's carrying has some sort of special power that she has to protect it from other magical beings who want to use that power for their own gain. Also, it could turn out that the pregnancy is a result of time - travel shenanigans, where she got pregnant in a different time period and now has to deal with the consequences in her current time.
Snow White might be initially suspicious, given their past history. But she could also show a more empathetic side and try to help Regina. Hook might be amused and make some snarky comments at first, but then offer his protection. Rumpelstiltskin could see it as an opportunity to manipulate Regina further, perhaps by offering her magic to ensure a safe pregnancy in exchange for favors.
The relationship could become stronger. Regina, who has had a difficult past, might find new hope and softness in the idea of having a family with the OC. They could start to rely on each other more, sharing fears and hopes about the future. For example, Regina could open up more about her own past traumas related to family, and the OC could comfort her, creating a deeper bond.
There's also 'Regina's Redemption through Archie'. In this fanfiction, Archie becomes a crucial figure in Regina's journey towards redemption. It shows how his kind and understanding nature can influence her to make better choices. It's really interesting to see their interactions unfold as the story progresses.
A possible plot twist is that the OC discovers that the pregnancy is not a natural occurrence but the result of some dark magic manipulation by an unknown enemy. This would make Regina and the OC go on a quest to find out who is behind it and how to reverse it if necessary. Meanwhile, they have to deal with the emotional turmoil of not knowing if the baby will be okay and whether they can trust their own feelings for each other.
In some fanfictions, Emma and Regina could develop a romantic relationship. Their complex history would add depth to such a story. They might have moments of jealousy when other characters show interest in one of them, and then have to confront their true feelings for each other.
Redemption is a very popular theme. Given Regina's complex character arc in the show, many fanfictions explore her journey towards redemption, how she tries to make up for her past wrongs and find a place in the world where she can be accepted and at peace.
Their relationship can be developed by having them share more personal secrets. For example, Regina could tell Henry more about her childhood before she became the Evil Queen. Henry, in turn, could share his dreams and fears for the future. This deepens their understanding of each other.
One popular aspect in Regina and Robin Hood fanfiction is their complex relationship. They have a connection that defies the odds. In many fanfictions, they start off as adversaries. Regina, with her dark past and powerful magic, and Robin Hood, the noble outlaw. But as the story progresses, their mutual understanding grows. Their relationship is often depicted as a slow - burn romance, filled with moments of hesitation, longing glances, and small acts of kindness that gradually break down the barriers between them.
One possible plot could be that the other characters in Storybrooke have to deal with the power vacuum left by Regina's death. Maybe her son Henry would struggle with his identity more as he no longer has his mother as an anchor. The Evil Queen's spells could start to go haywire without her there to control them, causing chaos in the town.