Perhaps Noel Kahn. He has always been a bit of a wild card in the story, and it would be an unexpected turn if he was the father. Also, Caleb could be a candidate. Given his relationships within the group, it would create interesting storylines. There's also the chance that it's an older character from Alison's past that we haven't fully explored yet.
One potential father could be Jason DiLaurentis. It would be a very scandalous and family - drama - filled situation if he were the father. Another option is that it's a character from outside the main group, like a visiting student or a new neighbor who had a brief encounter with Alison. And there's always the possibility that it's a character who has been in disguise all along and reveals himself as the father later in the fanfiction.
It might also be a character that the readers least expect. Maybe a character who has always been in the background, like a childhood friend who has always had unspoken feelings for Alison. The pregnancy could be the catalyst that brings these hidden feelings to the surface and reveals their connection.
One possible plot twist could be that the father of the baby is not who everyone initially suspects. Maybe it's a character who has been in the shadows all along. Another twist could be that Alison's pregnancy is part of a bigger conspiracy to take down her or her family. Or perhaps she discovers some magical or supernatural element related to her pregnancy that changes the whole story.
Another plot twist could be related to the health of the baby or Alison herself. There could be some complications during the pregnancy that force Alison to make difficult decisions. This could involve choosing between different medical treatments or dealing with the emotional stress of potential risks to the baby's well - being, and how it affects her relationships with those around her.
Another option could be a mysterious figure. For example, a character from another dimension or a new character introduced specifically for this plot twist. This could add an element of mystery and intrigue to the story.
It could be her long - time boyfriend. They've been in a loving relationship for a while, and this pregnancy could be the next step in their relationship journey. Maybe they've been talking about starting a family, and now it's finally happening.
Neji could be a potential father. Their long - standing friendship and mutual respect could have developed into a deeper relationship over time, leading to the pregnancy.
It could be her long - time friend Gary. They've known each other for a long time and there could have been some unspoken feelings between them that led to this situation.
It could be a long - time love interest like Stefan. Their relationship has had its ups and downs, and a pregnancy could add a whole new layer of complexity to their story.
It could be one of her close friends in the story. Maybe someone she has had a long - standing relationship with and the pregnancy was an unexpected but not entirely unwelcome result of their relationship.
Another option is that it could be a character who has been her friend for a long time. Their relationship could have evolved over time and led to this situation. For example, a close friend who has always been by her side and they had a moment of passion that resulted in the pregnancy.