Maybe Remus leaves because he feels unworthy. He has always seen himself as a danger and an outcast. Despite Tonks's love, he can't shake off his self - loathing. So, in the fanfiction, he leaves while Tonks is pregnant, leaving her heartbroken. However, their friends, like the members of the Order of the Phoenix, might try to convince Remus to come back and be a family with Tonks.
In this fanfiction, Remus could leave due to some dark influence or a misunderstanding. For example, he could be tricked by a dark wizard into believing that staying with Tonks and the baby would lead to their doom. Tonks, on the other hand, is left alone and pregnant, but she is a strong witch. She starts her own investigation to find out why Remus left and to bring him back.
Well, it could be about Teddy having a dream where he meets his parents. In the dream, Remus and Tonks are as he's always imagined them. They tell him how proud they are of him, even though they didn't get to see him grow up. This simple encounter could be a very moving and emotional one, with Teddy waking up with a newfound sense of purpose and connection to his parents.
Tonks would likely be extremely heartbroken. She loves Remus deeply and having him leave while she's pregnant would be a huge shock. She might first go through a period of denial, not believing that he's really gone. Then she would probably be angry, feeling betrayed by the man she loves.
One possible plot could be that Remus initially panics when he finds out Tonks is pregnant. He might worry about his werewolf nature and how it could affect the child. Tonks, on the other hand, is determined to have the baby and raise it with Remus. They could face challenges from the wizarding community due to Remus's condition, but with the support of their friends like Harry, Hermione, and Ron, they manage to overcome the difficulties and look forward to starting a family.
Well, one possibility could be that in this fanfiction, Lupin sees Hermione's intelligence and loyalty in a way that he feels a deeper connection with her compared to Tonks. Maybe Hermione helps him in some sort of magical research or during a difficult time at Hogwarts, and through those experiences, his feelings for her grow stronger than his feelings for Tonks.
One possible scenario in this fanfiction could be that Teddy shows some unique magical abilities that remind Remus and Tonks of their own magical heritages. Maybe Teddy can transform in a way that combines both werewolf and metamorphmagus traits, which would be a really interesting plot point. It could also explore how Remus and Tonks, who had such a tragic end in the original story, get to experience some happy moments with their son Teddy through the magic of fanfiction.
Fanfiction.net is a great place to start. It has a large collection of fanfictions about various characters, including Remus and Tonks. You can search by the characters' names or by tags related to their relationship or the Harry Potter universe in general.
Love against all odds is a very common theme. Given Remus' condition as a werewolf, they face a lot of opposition and prejudice. Fanfictions often explore how their love overcomes these difficulties.
One idea could be to focus on how they prepare for the baby's arrival. Maybe Remus is worried about his werewolf condition affecting the child, and Tonks has to constantly reassure him. They could start decorating the nursery with magical elements.
There's also 'Love in the Shadows'. This fanfic focuses on the more secretive aspects of their relationship. It portrays how they communicate in the midst of Voldemort's rising power, with Tonks using her skills as an Auror to protect Remus, and their love growing stronger through shared hardships.
A common plot point is Remus' struggle with his self - worth. He often doubts if he'll be a good father because of his werewolf condition. For example, in many fanfictions, he has internal monologues where he's worried about passing on his lycanthropy or being a bad influence. Another plot point is Tonks adjusting her Auror duties while pregnant. She has to balance her job and her pregnancy, which can lead to some tense situations with her superiors.