Another theme is the allure of the forbidden. Their relationship is often seen as something that goes against the norms, either in the vampire - human world or within their own communities. This adds a sense of danger and excitement. For example, in many fanfictions, they have to hide their relationship from others. Also, the theme of redemption is quite prevalent. Eric's dark nature often needs to be redeemed in some way through his love for Sookie. In some stories, he has to overcome his past deeds to be worthy of Sookie's love. This makes for some really engaging character development.
One popular 'Dark Eric and Sookie Fanfiction' is 'The Viking's Bride'. It delves deep into their complex relationship in a rather dark and alluring way.
One common theme could be the challenges they face as a couple during the pregnancy. Maybe dealing with how their relationship changes or how their families and friends react.
Well, there's a fanfiction called 'Sookie's Married to Eric'. In this story, the author focuses on how Sookie adapts to the vampire world now that she's married to Eric. It has some really unique takes on their relationship. There's also a piece where they face a threat together as a married couple, which really shows their bond. I can't remember the exact title, but it was really engaging. Another one might be 'Our Married Life, Sookie and Eric' which has a lot of domestic scenes that are both heart - warming and exciting.
Love and loyalty are common themes. Their relationship is often tested, but they remain loyal to each other in many stories. For example, in some fanfics, Sookie has to choose between Eric and her human friends, and her loyalty to Eric shines through.
The theme of immortality and mortality is also prevalent. Godric and Eric are immortal vampires, while Sookie is a mortal human. The fanfictions often play with this contrast, like how Sookie views the vampires' eternal existence, and how the vampires see the fleeting nature of Sookie's life. It adds a layer of melancholy and urgency to their relationships.
I'm sorry, I don't have specific 'eric and sookie pregnant fanfiction' stories to recommend directly. You can try searching on fanfiction websites like Archive of Our Own. There are usually a lot of fan - created stories about various characters, and you might be able to find what you're looking for there.