One type of fanfiction could be where Sam gets hurt during a hunt. Maybe he's attacked by a powerful supernatural creature and has to deal with a serious injury while Dean tries to find a way to save him. It could explore his physical and mental pain, and how he copes with the situation.
There could also be a fanfiction where Sam is emotionally hurt. For example, if he discovers that someone he trusted has betrayed him. This would cause him to question his relationships and his role in the fight against the supernatural. It would be a more character - driven story, focusing on Sam's internal struggle.
In some fanfictions, Sam could be hurt by a spell gone wrong. This might lead to him losing his memories or having his powers affected in a negative way. His friends in the Supernatural world would then have to figure out how to reverse the effects and help Sam get back to his normal self.
Perhaps Sam gets hurt while trying to protect a civilian. He jumps in front of a werewolf's attack meant for someone else. This would show his selfless nature. The local hunters in the area might not trust Sam and Dean at first, but seeing Sam's sacrifice could change their minds, adding an interesting dynamic to the story.
Another aspect is how it affects the relationships in the story. If Sam is hurt, it can put a strain on his relationship with Dean. Dean might feel guilty for not being able to protect him. Or it could strengthen their bond as Dean devotes all his time to taking care of Sam and making sure he gets better.
One common plotline could be Sam getting physically hurt during a hunt and his brother Dean having to take care of him. For example, in some fanfictions, Sam might be injured by a supernatural creature like a werewolf. Another plotline could involve Sam being hurt emotionally, perhaps due to a betrayal within the hunting community or a difficult decision he has to make. Sometimes, fanfiction writers explore Sam getting hurt as a result of a spell gone wrong, which then leads to a series of events where the other characters have to find a way to reverse the effects.
Sometimes it's due to Dean's overprotectiveness. He might think he's doing what's best for Sam but in the process, his actions end up causing harm. For instance, he could keep Sam from a mission that Sam believes is important, and in the struggle, Sam gets hurt.
He could be poisoned. There are many supernatural creatures in the Supernatural universe that could use poison. For example, a witch could create a poisoned potion and trick Sam into drinking it.
A possible fanfiction plot could start with Dean being seriously hurt in a car accident on their way back from a hunt. Sam is distraught but quickly springs into action. He calls their hunter friends for help and takes Dean to the nearest safe house. There, he nurses Dean back to health. Sam is extra vigilant, setting up protective wards around the house and being overly cautious about any strangers approaching. He also spends time talking to Dean, helping him deal with the trauma of the accident both physically and mentally.
Yes, there are. But it really depends on what you're looking for in a fanfiction. If you like drama, there are those that will amp up the tension between Sam and the other characters due to this pregnancy. If you prefer a more character - study - like approach, you can find ones that really analyze how Sam and Ruby change as individuals because of this new situation.
Well, it could be that Sam sees potential for redemption in those who hurt him, or he might feel obligated to try and change them for the better. Another possibility is that he's trapped in a situation where he has no other choice.
In fanfiction, if Sam was kidnapped, it could lead to a very intense story. Dean would surely go on a rampage to find him. Maybe Sam was kidnapped by a powerful demon who wants to use him for some dark ritual. It could also be a new, unknown enemy who has a vendetta against the Winchesters.
Some writers will use symbolism to show Sam's pain. For example, if he's been hurt by a dark magic spell, they might describe the darkening of his eyes or a shadow that seems to follow him. And in terms of his emotional pain, they could compare it to a storm brewing inside him, with his thoughts and feelings churning like thunderclouds.