Often, there is a theme of anticipation and future - building. Since the OC is pregnant, the fanfic may focus on what the future holds for their family. This could involve Thorin's thoughts on raising a child, his hopes for the heir, and how their relationship evolves as they prepare for parenthood. Additionally, the fanfic might touch on how the pregnancy affects the OC's role in the community or among Thorin's followers.
One common theme is redemption. Often, the OC helps Thorin on his journey towards redemption, especially considering his greed in the original story. For example, in some fics, the OC might be the one to make Thorin see the error of his ways regarding the Arkenstone.
One common theme is the exploration of their relationship under this new and unexpected circumstance. Another could be how the characters from Middle - earth react to this rather unorthodox situation. Also, there might be themes related to the challenges of pregnancy in a fantasy setting.
A common theme is adventure. Since Thorin is often on a quest in Middle - earth, the oc gets swept up in these adventures. For example, they might be traveling with him to reclaim Erebor. Another theme is love against the odds. Thorin is a dwarf king with many responsibilities, and the oc is an outsider, so their relationship faces many challenges.
I'm not sure which specific Thorin OC pregnant fanfics are available. You could try searching on fanfic platforms like Archive of Our Own. They have a large collection of fanfics, and you can filter by the relevant tags to find ones about Thorin and a pregnant original character.
One common theme is adventure. Since Thorin is often on some sort of quest, the OC usually gets involved in these grand adventures. They might face orcs, dragons, or other perils together. Another theme is redemption. Thorin has his own flaws and sometimes the OC helps him in his journey of self - discovery and redemption.
Common themes in 'x oc pregnant fanfic' often revolve around the emotional aspect. The oc may experience a range of emotions from fear to joy. There can be a theme of protection, where 'x' becomes very protective of the oc and the unborn child. Social implications can also be a theme, like how the couple is perceived in their community or within their fandom. Additionally, there could be a theme of growth, both for the relationship between 'x' and the oc and for the individual characters as they step into new roles as parents - to - be.
The themes usually involve the reimagining of the story. A female Bilbo brings a different energy, so there's a theme of transformation in the story. Love and loyalty are also common themes. Whether it's the loyalty to the group or the love that might develop between Bilbo and Thorin. And there's the theme of identity. The female Bilbo has to figure out her place in the world of dwarves and hobbits while being in a relationship with Thorin.
Themes like acceptance play a major role. The OC has to be accepted by Thorin and Company, and vice versa. There's also the theme of purpose. In the modern world, what is Thorin's purpose? What about the OC? They may find that their purposes are intertwined. And the theme of mystery is often present. There could be a mystery surrounding the dwarves' appearance in the modern world or something related to the OC's past that they all have to figure out together.
Adventure is a common theme. Since Thorin is often on a quest, the OC can be part of that journey. For instance, they could face orcs together, and this shared danger brings them closer.
Love and support are very common themes. Steve is often depicted as being extremely supportive of the OC during her pregnancy, showing his caring and protective nature.