There are some. For example, 'Vampiric Love at Hogwarts' is a fanfiction in this genre. In it, Harry and Ginny's vampire transformation brings a whole new dynamic to the wizarding world. They struggle to keep their secret while also trying to figure out how to use their new powers for good. It's a really unique take on the characters.
One common theme is secrecy. They have to hide their vampire nature from others in the wizarding world. Another is the struggle with their new identity. For example, they might have to deal with changes in their relationships. Also, power and its control. Their vampiric powers can be both a strength and a danger.
Perhaps there could be a vampire clan leader named Viktor. He would be responsible for Harry's upbringing in the vampire community. He would teach Harry about the rules and traditions of the vampires. There might also be a young and rebellious vampire, Damien, who becomes like an older brother to Harry and shows him the ropes in a more unconventional way.
Yes, there are likely fanfictions out there with the concept of the 'father of vampires' in the Harry Potter universe. Fanfiction writers often come up with creative and unique ideas that blend different elements of the HP world. You can try searching on fanfiction websites like FanFiction.net or Archive of Our Own to find such stories.
Ginny might support Harry by simply being there for him. In the face of everyone else turning their backs, her presence can be a great comfort. For example, she could sit with him at meals when no one else will.
One possible reason could be miscommunication. Maybe Ginny feels neglected by Harry because he's so caught up in his own heroic deeds and doesn't pay enough attention to her. So she might seek comfort or excitement elsewhere.
Perhaps some well - known vampire characters from other vampire - related stories could be incorporated. However, they would need to be adapted to fit into the Harry Potter universe. For example, a vampire like Lestat from 'The Vampire Chronicles' could be reimagined as a character in this fanfiction. He could bring his own brand of charm and danger to the story.
There could be many interesting fanfictions on this topic. One idea could be that in this fanfiction, the 'force' might be some sort of magical or emotional force that binds Harry and Ginny even closer during her pregnancy. It could explore how they deal with the impending arrival of their baby while also facing challenges related to this special force.
Ginny might initially be heartbroken. She could retreat into herself, feeling betrayed and confused. In some fanfictions, she may cut off all contact with Harry immediately.