Well, perhaps in the fanfiction, the pregnancy could be a catalyst for them to start thinking about their future more seriously. They might start planning a life together off the ship, looking for a place to settle down. It could also lead to some comical situations, like Jack trying to build a makeshift crib in their small cabin.
Perhaps they find out about the pregnancy in a very unique way. For example, Miko has been feeling strange and Jack, being the observant one, takes her to the doctor. It turns out she's pregnant. Then they start a journey of preparing for the baby. They attend parenting classes together, read books on pregnancy and child - rearing, and slowly build their confidence as future parents.
One idea could be that they face challenges from their families who have different expectations for their future. Maybe Rose's family is more traditional and has concerns about their young age and financial stability. Another could be that they discover some unexpected medical issues during the pregnancy, which brings them closer together as they deal with the stress.
Well, a plot could revolve around Aku trying to keep his pregnancy a secret from Samurai Jack. He might be worried that Jack would use this new situation to his advantage. And then there could be a sub - plot about Aku having strange cravings that lead him to unexpected places in the world of the fanfiction, causing chaos in different ways.
One idea could be that their baby grows up with a love for the sea, just like their parents' fateful encounter on the Titanic. Maybe the baby discovers a hidden diary that details their parents' story and becomes inspired to preserve the memory of the Titanic in a new way, like through art or historical research.
One idea could be that Rose's pregnancy brings new challenges to her training at the Vampire Academy. Maybe she has to deal with physical limitations while still trying to prove herself. Another could be that her pregnancy causes a stir among the different vampire factions, some seeing it as a sign of hope and others as a threat.
Well, perhaps in the fanfiction, Ron and Hermione discover that Rose has some unique magical abilities even before she is born. This causes a stir in the wizarding world, and they have to deal with unwanted attention from the Ministry of Magic. At the same time, they are also trying to balance their normal lives, like Ron still working at Weasley's Wizard Wheezes and Hermione doing research at the Ministry. They have to find a way to protect their family while also living their lives.
One idea could be that Jack and Rapunzel are living in a small, peaceful village when they discover Rapunzel is pregnant. They then have to face the challenges of preparing for a new life together, like building a bigger home. Another could be that they are on a magical adventure while Rapunzel is pregnant, and they meet different magical creatures who offer their help and wisdom for the upcoming baby.
A plot could revolve around the mystery of who the father is, if it's not immediately obvious. This could lead to some drama and speculation among the characters. Or it could be about her journey of self - discovery during pregnancy. She might learn new things about herself, her strength, and her capacity to love. Maybe she also has to deal with changes in her relationships because of the pregnancy.
A possible plot could be that Rose discovers she has some special magical ability related to her pregnancy. For example, she might be able to communicate with the unborn child through a unique form of magic. This could lead to all sorts of adventures as she tries to understand this new power and what it means for her and the baby. Or perhaps there are dark forces that are interested in her unborn child because of a prophecy, and Rose has to fight to protect her baby throughout her pregnancy.
One idea could be that they discover the pregnancy in the middle of an adventure. Maybe they're on a planet with some strange energy that affects the Doctor's biology in an unexpected way, leading to the pregnancy. They then have to deal with the challenges of protecting the unborn child while also facing the usual threats in the universe.