You can start by looking on Archive of Our Own (AO3). It has a large collection of Supernatural fanfiction, including those with the 'dean winchester oc pregnant' theme. Just use their search function and type in relevant keywords.
One popular 'dean winchester oc pregnant fanfiction' might be 'The Unexpected Miracle'. In it, the original character (oc) finds herself pregnant and Dean is initially shocked but then becomes very protective. It has great character development and emotional depth.
One great 'Dean Winchester and OC Fanfiction' is 'A Hunter's Heart'. It has a well - developed OC who teams up with Dean on a hunt. The story is filled with action and the chemistry between them is really engaging.
One common theme is the idea of the oc being a powerful ally or a love interest for Dean. For example, many fanfictions have an oc with special powers that help Dean in his hunts.
To write a good 'Dean Winchester and OC Fanfiction', you need to understand the character of Dean Winchester really well. Know his mannerisms, his sense of humor, and his loyalty to his family. When you introduce your OC, make sure she complements Dean's character. You can also add some Supernatural elements that are not too over - the - top but still exciting. For instance, a new type of monster that they have to face together. Also, develop their relationship gradually, from strangers to friends to maybe something more.
There could be a fanfiction where Dean's pregnancy is a result of some sort of supernatural curse. In this story, he has to find a way to break the curse while dealing with the pregnancy. This might involve seeking out a powerful witch or an ancient artifact. Along the way, he discovers new things about himself and his relationships, especially with Castiel who might offer some angelic help or at least moral support.
One common theme is adventure. Since Dean Winchester is often involved in hunting and saving the world, the OC usually gets dragged into these adventures. Another theme is love. It could be a slow - burn love or a sudden attraction between them.
Another theme is acceptance. Dean has a lot of baggage from his past, and the OC wife has to accept who he is. In some fanfictions, this is shown through her being understanding when he has nightmares about his time in Hell or when he gets overly protective. It's about her loving all parts of him.
First, develop a strong character for the daughter. Give her unique traits, like a particular sense of humor or a special skill. For example, she could be an amazing mechanic like her father. Then, create a conflict. It could be an internal conflict, like she's torn between her love for her family and her desire for a normal life. Or an external conflict, such as a new and powerful supernatural enemy that specifically targets her.
Another way is to join fan communities dedicated to Supernatural. There are forums and groups on platforms like Reddit or Facebook. Ask the members if they know any good dean winchester is pregnant fanfiction. They might be able to recommend some really great and hidden gems that you wouldn't find through a simple web search.