I'm not entirely sure which specific 'chris x wesker infected fanfic' you are referring to. However, in general, such fanfics often explore the relationship between the characters Chris and Wesker in the context of some sort of infection. It could be a creative take on how their characters interact, develop, or change due to this new element in their fictional world.
The fanfiction might also focus on their shared history. They've both been through a lot in the Resident Evil world. There could be scenarios where they remember past encounters and how those memories shape their current interactions. For example, perhaps a past mission where they had a moment of mutual respect that is now overshadowed by their current enmity. Writers can use this to build a more in - depth and nuanced relationship in the fanfiction.
One possible plotline could be that Chris gets infected and Wesker tries to control or use him for his own evil plans. Another could be that they both get infected in different ways and have to find a cure together while dealing with their changing bodies and relationship.
Well, it could be about Chris trying to find a cure for the virus that Wesker has been involved in spreading. Maybe Chris is on a mission to stop Wesker from using the virus for some evil plan, and during this, there are some intense confrontations and perhaps a bit of unexpected teamwork when they realize a greater threat related to the virus.
The main characters are Chris, who is known for his combat skills and sense of justice, and Wesker. Wesker is a complex character. He may be the antagonist in the fanfic due to his connection with the virus, but his character can also have some depth and hidden motives that make him more than just a simple villain. And of course, the virus itself can almost be considered a character in a way as it drives the actions and interactions of Chris and Wesker.
One popular trope is the 'enemies - to - lovers' scenario. Given their antagonistic relationship in the main Resident Evil storyline, it's not uncommon for fanfiction to explore the idea of them gradually developing feelings for each other. Another trope is the 'power imbalance' where Wesker's superior strength and abilities create a dynamic where Chris has to constantly struggle to keep up.
Protection could be a common theme. Since the reader is pregnant, Albert Wesker might be portrayed as being very protective of her. Maybe he uses his skills and power to keep her and the unborn child safe from various threats.
Another theme is adventure. Given Wesker's involvement in various dangerous and high - stakes situations in the Resident Evil universe, the stories might take the reader on an adventure with him. They could be on a mission to stop a new virus outbreak or dealing with other threats together. This allows for a lot of action - packed scenes and the development of the relationship between the two characters. And often, there is a romantic undertone to these adventures, as the relationship between the reader and Wesker develops during these events.
I'm not sure of specific 'albert wesker x pregnant reader fanfiction' offhand. But you can try searching on popular fanfiction websites like Archive of Our Own. They usually have a wide variety of fanfictions, and you might be able to find some related to this pairing there.
Another place could be Wattpad. It has a wide variety of fanfiction, including those related to Albert Wesker and a reader - insert. However, the quality may vary, so you might need to do some sifting through the stories to find the really good ones. Some writers on Wattpad are very dedicated and create interesting plotlines for this type of pairing.