A possible plotline could be centered around Severus seeking help from unexpected sources. Maybe he turns to some of the more neutral or even good - aligned wizards and witches for advice or assistance, since he can't rely on Voldemort or the Death Eaters completely. The pregnancy could also be a catalyst for Severus to re - evaluate his life and his actions. He might start to question his past decisions and try to find a way to create a better future for himself and the unborn child, all while dealing with the stigma and danger associated with such a situation in the wizarding world which is full of secrets and power struggles.
There might be some out there. Fanfiction writers can come up with all sorts of creative and sometimes out - of - the - ordinary ideas. However, this one seems quite unique and might not be as widespread as more common fanfiction themes in the Harry Potter universe. Some smaller, more niche fanfiction communities might be a place to look, but again, it's hard to say for sure.
One possible plotline could be that it's the result of some strange magic or alien technology. Maybe an enemy uses a device on Goku as part of a plan to weaken him or create chaos. Another could be a more comical take where Goku accidentally ingests something that causes this unusual situation.
Another plotline might be that in a world where the laws of nature are different for certain characters, Magnus and Alec decide to have a child in this unique way. The story could then focus on how they deal with the reactions of their friends and family, and also the challenges of Alec's pregnancy, like his changing body and emotions. It could also involve them preparing for the arrival of the baby, from choosing a name to setting up a nursery.
One possible plotline could be the chaos and shock that spreads throughout the ninja world when the news gets out. There would be reactions from their friends and enemies alike. Another could be Naruto and Karin trying to figure out how to handle the situation while also dealing with their own feelings for each other.
One possible plotline could be Sasuke discovers he's pregnant while on a solo mission. He then has to figure out how to deal with this situation while also hiding it from his enemies. Another could be that it's the result of some sort of magic or experimental jutsu gone wrong. He then has to face the reactions of his friends and family, especially Naruto, who might be shocked but also supportive.
Maybe the story could focus on Harry trying to find a way to reverse the situation. He could go on a quest to find some ancient magic or a powerful wizard who might be able to help. There could also be a plot where the Ministry of Magic gets involved, either trying to cover it up or use it as a weapon against Voldemort. And of course, there would be the internal struggle for Harry, dealing with his own feelings about Voldemort and this unexpected pregnancy.
In some fanfictions, it might be that Severus leaves due to some external threat that he believes will harm Harry and the unborn child if he stays. So, he sacrifices his relationship with Harry for their safety. Harry, on the other hand, is left heartbroken but determined to raise the child alone. Later, Severus might return when he realizes he can protect them after all, leading to a reconciliation.
One possible plotline could be that Harry and Cho initially struggle with the news. They might face judgment from their friends and the wizarding community. Harry, being the responsible person he is, would likely try to support Cho through the pregnancy. They could also decide to keep it a secret at first to avoid the chaos it would cause at Hogwarts.
Well, perhaps the plot could revolve around Naruto trying to figure out how such a thing could even happen. It could involve some sort of strange jutsu gone wrong that affected the bunshin in this way. And then there could be a search for a way to reverse it, all while Naruto is dealing with the emotional turmoil of the situation. He might also have to hide it from his enemies as it could be seen as a weakness. This could lead to some tense and comical moments as he tries to keep it a secret.
The idea of Voldemort getting Harry pregnant goes against the original nature and themes of the Harry Potter series. J.K. Rowling's work is mainly about good vs. evil, friendship, and the fight against dark magic. So, while there might be some extremely non - canonical and out - there fanfiction on this very strange and inappropriate topic, it is not something that is in line with the spirit of the original story.