Yes, there are likely some 'Lois Lane pregnant' fanfictions in the Smallville fandom. Fanfiction writers often explore different scenarios, and a pregnancy for Lois Lane is an interesting plot point that can add drama, character development, and new storylines. However, the quality and content can vary greatly among different fanfictions.
A frequent theme is the support system around Lois. It could be about her family, like her father's reaction, or her friends in Smallville. Also, the theme of anticipation and preparation for the baby is common. How Lois and those around her get ready for the new addition to their lives, from setting up a nursery to emotional preparations.
Smallville has elements of the Superman mythos, but it's more of a unique take on the character's early years. It's not the sole authentic version of his story. Other comics and adaptations offer different perspectives.