In fanfic, the concept of ethics can be quite complex. From a general moral standpoint, getting a girl pregnant at a young age as might be the case in a 'Harry gets girls pregnant fanfic' is often considered unethical in real - world values. However, in the realm of fanfic, it's a fictional exploration. Some might argue that it's a way to explore different storylines and character developments, but it still might make some readers uncomfortable given the serious nature of the topic.
It's difficult to say whether there is a 'harry gets pregnant by bill fanfic'. The world of fanfiction is so large and diverse that almost any concept can be explored. But considering the nature of the Harry Potter series, which is mainly focused on magic, adventure, and the fight against evil, this type of plotline seems rather uncharacteristic. Also, the Harry Potter fandom has certain unspoken norms and expectations, and this might not fit well within those. However, with the freedom that fanfic authors have, it's not entirely impossible that such a fic exists.
There could potentially be a 'harry gets pregnant by bull' fanfic out there in the vast world of fanfiction. However, it's not something that would be considered mainstream or in line with typical fanfic themes. It might exist in some more niche or experimental corners of the fanfic community, but I haven't come across it myself.
This kind of fanfic involves very abnormal and often not - acceptable scenarios. In the world of fanfiction, there are a lot of works that range from the creative to the downright strange. But this concept is so far - fetched that it's likely not a common or well - known fanfic. It also might violate some basic norms and ethics within the fanfic community.
I'm not aware of any such fanfic. Fanfiction often contains a wide variety of strange and inappropriate concepts, but this one seems rather extreme and goes against the nature of the original Harry Potter story in terms of the characters' relationships.
The plot might involve them trying to keep it a secret at first. Harry would be worried about how it would impact his fight against Voldemort. Tonks, on the other hand, might be excited but also scared. They'd have to figure out how to balance their relationship, the coming baby, and their duties in the wizarding world.
There might be some fanfics with a similar concept but made appropriate for general audiences. Some fanfic authors may take the idea and twist it into a more platonic or magical - misadventure - type story that doesn't involve any inappropriate or adult - themed elements. However, it can be quite difficult to find as the original idea is rather out - of - the - box and often explored in more mature fanfic areas.
The main characters are clearly Harry and Susan. Harry is the one who gets Susan pregnant, so he's likely to be a central figure in the story as he has to deal with the consequences of his actions. Susan, being the one who is pregnant, will also be a main character as she has to go through the physical and emotional changes that come with pregnancy.
A 'harry gets pregnant by bill fanfic' would be a very unconventional take on the Harry Potter world. Given the fact that both Harry and Bill are male characters in the original series, for this to happen in a fanfic, it would likely involve some form of magical or otherworldly intervention. Maybe a dark magic experiment that backfires, or a strange ancient spell that has unforeseen consequences. It would also have to deal with the social and emotional implications within the wizarding world, which would be a huge departure from the normal storylines.
One possible plot could be that it starts with an unexpected encounter between Harry and Gabrielle. Maybe they are in a situation where they have to work closely together, like in a magical mission. As they spend more time together, feelings develop and one thing leads to another, resulting in Gabrielle getting pregnant. Then the story could focus on how they deal with the news, the reactions of their friends and families, and their own fears and hopes for the future.