In this fanfiction, Snape could be in a situation where he is magically bound to give birth as part of a prophecy or a curse. He chooses to be alone because he is a solitary and proud character. He might have set up a hidden room in the dungeons filled with all the necessary items for childbirth. As the contractions start, he uses his wand to perform spells for pain relief and to assist with the birth. After the baby is born, he then has to figure out how to raise the child in the wizarding world without drawing too much attention to this extraordinary situation.
One possible plot could be that Snape discovers he has a unique magical ability that allows him to carry a child. He might keep it a secret from everyone in Hogwarts due to fear of ridicule. As he nears the time of giving birth, he would have to find a secluded place within the castle or in the Forbidden Forest. He would endure the pain alone, using his own potions and magic to ease the process as much as possible.
Well, perhaps in the fanfiction, Snape was the subject of a dark magic experiment that resulted in his unexpected pregnancy. He decides to go through it alone because he doesn't trust anyone. He spends months preparing in secret, brewing special potions to keep himself and the baby healthy. When the time comes, he barricades himself in his private chambers and uses his knowledge of magic to ensure a safe delivery, all while grappling with the emotional turmoil of this strange situation.
Snape would probably use his knowledge of potions. He might have brewed a special pain - relieving potion in advance. He would also use his Occlumency skills to try and block out some of the pain mentally. Since he is a strong - willed character, he would grit his teeth and endure it as best he could while focusing on the task at hand, which is giving birth safely.
One possible plot twist could be that Bella discovers a hidden power within herself during the birth. For example, she might be able to communicate with the baby in a telepathic way, which gives her the strength to endure the pain alone. Another twist could be that there are unexpected visitors who watch from a distance but choose not to interfere, adding an element of mystery to the story.
One possibility is that in the fanfiction, she might be in a situation where she has cut herself off from her friends for some noble reason. Maybe she wants to protect them from some dark magic that she believes will target her during childbirth. Another reason could be that she's on a secret mission and has no choice but to be alone when she gives birth.
It could be that the father is an unknown wizard who Harry had a brief encounter with. Maybe it was a one - time magical connection that led to the pregnancy.
Well, a plotline might involve Snape initially being in denial about the pregnancy. As it progresses, he could start to form an unexpected bond with the unborn child. There could also be a plot where other characters find out and either support him or try to use it against him. Maybe Voldemort discovers it and tries to manipulate Snape in a new way because of this situation.
Perhaps in the 'harry gives birth at dursleys fanfiction', there's a new form of magic introduced. Harry could have been affected by a magical experiment that causes this strange phenomenon. The Dursleys, who have always mistreated Harry, now have to face the consequences of having such a unique and unheard - of event happening in their house. They might be in a state of panic and confusion as they try to figure out what to do.
The plot could also involve the father of the baby being a mysterious figure. Maybe he's from a far - off land that Elsa visited during her adventures after the events of the Frozen movies. And as she gives birth, the baby could inherit some of her ice powers, which would lead to a whole new set of challenges and adventures for Elsa as a mother, like teaching the baby to control its powers from a very young age.
One possible plot could be that Sakura has a difficult birth. Naruto is by her side, worried sick. Their friends from the village are also there, waiting anxiously. Maybe there are some complications during the birth, and Sakura has to draw on her inner strength as a kunoichi. And in the end, she gives birth to a healthy baby, which brings great joy to the whole village.
Perhaps it could involve some sort of magical or scientific experiment gone wrong that results in Tony being able to give birth. Peter could be the result of a genetic manipulation within Tony's body, and the story might then focus on how they adapt to this strange new situation.
Perhaps the fanfiction focuses on how the baby changes the relationships in Naruto's life. Her relationship with Sasuke could be affected, whether they are friends or something more. The baby could also bring new unity among the ninja villages as everyone comes together to protect the new life. And the story could explore how female Naruto passes on her ninja values to her child from a very young age.