It's possible. Fanfiction often takes existing characters and gives them new storylines. In the case of Optimus Prime and Arcee, a 'pregnant' fanfiction could be about them having a new form of life or a project that they are nurturing together, which is presented as a pregnancy - like concept. You may need to do some digging through various fanfiction communities and websites to find one that suits your taste and is suitable for all viewers.
The bond between Optimus and Arcee in fanfiction can be really strong. They are both iconic characters in the Transformers world. A common theme in fanfictions is their loyalty to each other. This loyalty is shown through their actions in battles. For instance, Arcee would never leave Optimus' side when he is in a tough situation, and vice versa.
Optimus and Arcee have a very interesting relationship in the Transformers universe. They are comrades, often fighting side by side against the Decepticons. In fanfiction, their relationship can be explored in many ways. Some might write about their deep friendship and mutual respect. For example, a story could focus on how they rely on each other during a difficult battle. They communicate without words, understanding each other's battle strategies instinctively.
One great fanfiction could be about Optimus and Arcee going on a dangerous mission together. They face numerous challenges, like battling a powerful new Decepticon. Their teamwork and trust in each other are put to the test. Arcee's speed and agility combined with Optimus' strength make them a formidable duo. Along the way, they might have some deep conversations about the future of their race and their place in the war.
One possible fanfiction could be about Arcee and Optimus teaming up for a dangerous mission. They might face a powerful new enemy that neither of them has encountered before. Their combined skills and trust in each other would be crucial in overcoming the challenges. For example, Arcee's agility and Optimus' strength could be used in a complementary way to defeat the foe.
Perhaps a fanfiction where Arcee has to save Optimus Prime from a mind - controlling device. She has to fight against his altered self and find a way to break the control. This would show her determination and loyalty to Optimus.
One possible theme could be about creation and new beginnings. Maybe they are creating a new type of Transformer, and the process is symbolized as a pregnancy. Another theme could be about the bond between them growing stronger as they 'await' this new creation.
The theme of sacrifice often appears in fanfictions about them. They are willing to put themselves in harm's way for the greater good. This could be shown in a scenario where they have to sacrifice a strategic position to save a group of innocent Autobots. Also, the theme of redemption can be explored, especially if a character from their past resurfaces and they have to decide whether to forgive or not.
One interesting Arcee and Optimus fanfiction could be a story where they team up against a new, powerful Decepticon threat. In this fic, Arcee's agility and Optimus' strength complement each other perfectly as they battle through different terrains to protect the Autobot base.
Perhaps a fanfiction where Arcee and Optimus are transported to an alternate dimension. In this new world, they have to figure out how to get back home while also dealing with the strange new rules and inhabitants. They might find that their relationship is put to the test as they face unfamiliar and often dangerous situations. They could also learn new things about each other that they didn't know before.