There might be. Fanfiction is a very diverse genre. A family - friendly take on this could involve some sort of magical mix - up. For instance, a spell gone wrong that makes it seem like Percy could be the cause of Aphrodite being pregnant. The story could then revolve around the characters trying to reverse the spell and the comical situations that come up during the process.
You can try looking on fanfiction websites such as Archive of Our Own (AO3). It has a large collection of various fanfictions, and there's a good chance you'll find some related to Aphrodite being pregnant there. Just use the search function and type in relevant keywords like 'Aphrodite pregnant'.
One popular Aphrodite pregnant fanfiction might be the one where it explores the reactions of the other gods and goddesses. It could show how Zeus might react to the news, whether with concern or with some political plotting in mind. This type of fanfiction often delves into the complex relationships within the pantheon.
One common theme is secrecy. Since their relationship was often scandalous among the gods, in many fanfictions they try to keep the pregnancy a secret at first. For example, they might worry about Zeus's reaction.
In a 'Percy and Aphrodite pregnant fanfiction', it could start with Aphrodite having a premonition about a special child that could only be born if she and Percy were to have a union. She then manipulates the situation in a very Aphrodite - like way to make it happen. Percy, on the other hand, is a hero with his own set of values. When he discovers Aphrodite is pregnant, he has to balance his loyalty to his friends, his place in the demigod world, and his new - found role as a potential father. The story could explore the power dynamics between a demigod and a goddess, as well as the themes of love, fate, and responsibility.
The main antagonists could be some of the other gods who are jealous of Aphrodite's special situation with Percy. For example, Hera might not like the idea of Aphrodite having a child with a demigod, as it goes against the normal order of things in the godly realm.
One interesting fanfiction could be 'The Secret of Ares and Aphrodite's Unborn'. It explores how the other gods react to the news of Aphrodite's pregnancy. It delves into the complex relationships among the deities in a creative way.
Another possibility is Hephaestus. Since he was Aphrodite's husband in the original mythology. In the fanfiction, their relationship could have taken an unexpected turn leading to the pregnancy. This could also add a layer of drama as Hephaestus might be overjoyed while Aphrodite could have mixed feelings due to her complex nature.
I'm not sure if there are a lot of such specific fanfictions. Fanfiction varies greatly, and this is a rather unique concept. You could try searching on major fanfiction platforms like Archive of Our Own or FanFiction.net. Maybe look for tags related to Percy Jackson, Aphrodite, and pregnancy to narrow down your search.
One possibility could be that the pregnancy causes chaos in the world of the gods. Aphrodite's pregnancy might disrupt the balance of power among the deities. For example, other gods might be worried about what kind of being her child will be and how it will affect their own status or the future of the world. It could also lead to interesting interactions between Aphrodite and other characters like Percy. Maybe Percy gets involved in protecting her during her pregnancy from those who might want to harm her or the unborn child.