Ron's reaction would be a complex mix of emotions. Given his insecurities at times, he might initially worry about whether he'll be a good father. However, his love for Hermione would quickly override those doubts. He'd likely tell her how much he loves her and that they're going to have an amazing adventure together as parents. He'd probably also think about his own family, like how his mum will be so excited to have another grandchild, and he might start sharing his thoughts about names with Hermione, all while still being in a bit of a daze from the big news.
Ron would probably be shocked at first. He might stutter and not know what to say immediately. Then, a big grin would spread across his face as the news sinks in, and he'd pull Hermione into a tight embrace, telling her how happy he is.
Well, Ron has always had a bit of an impulsive side. So, when Hermione tells him she's pregnant, he could go through a range of emotions very quickly. He might start out with disbelief, like 'Are you sure, Hermione?' But once he realizes it's true, he'd be over the moon. He'd start making all these plans in his head about being a great dad, like teaching their kid how to play wizard chess and all the cool things he knows. He'd also become super protective of Hermione right away.
He could also be heartbroken. Ron might withdraw into himself, spending a lot of time alone in his room at the Burrow, not wanting to talk to anyone. He may start to doubt his self - worth, thinking that he wasn't good enough for Hermione.
Perhaps she tries to find them right away. Using her intelligence and resourcefulness, she starts to search for any clues as to where they might have gone. She could ask other friends, like Neville or Luna, if they have seen Harry and Ron. And she might be determined to bring them back, not willing to give up on their friendship easily.
Hermione would probably be extremely hurt. She's a very loyal person, and to have Ron cheat on her would shatter her trust. She might become withdrawn, not wanting to talk to anyone at first, and just try to process the pain on her own. Then she decides to run to Lucius, perhaps because she feels she has nowhere else to turn, or she thinks Lucius can offer her some sort of solution or support.
She might be heartbroken. Hermione is a strong - willed character, but being cheated on would surely shatter her. She could initially be in disbelief, given her trust in Ron. Then, she might become angry and start to distance herself from Ron, focusing more on her own studies or other relationships, like her friendship with Sirius.
Hermione would likely be very angry at first. She is a strong - willed character and being kidnapped would go against all her principles of freedom and rights. She would probably try to reason with Ron immediately, using her logical arguments to make him see how wrong his actions are.
She might feel heartbroken. In many fanfictions, Hermione has deep feelings for Ron, so seeing him with Lavender could shatter her world. She could initially be in shock and disbelief, and then it might turn into anger or deep sadness as she tries to come to terms with what she saw.
At the beginning, Ron would likely be in shock. He had always thought he and Hermione had a special bond. After the shock, he might become a bit bitter. However, his friends, like Harry, would probably try to cheer him up and help him see that there are other things in life. Eventually, Ron might find a new purpose in his life, whether it's in his magical studies or in exploring new parts of the wizarding world, and try to move on from Hermione.
Another way she could react is by distancing herself completely. She would stop trying to be part of their group and start creating her own identity at Hogwarts. She might explore parts of the castle she's never been to before, find new study nooks, and interact with students she's never really talked to, all while trying to forget about Ron and Harry's cold treatment.
Hermione's friends, like Harry, would likely be very protective of her. They might try to keep the news from spreading too far and help Hermione in any way they can. As for Draco, his family's reaction could be complicated. They might see this as an opportunity to gain some sort of advantage over the Weasleys, or they might be more sympathetic to Hermione's situation depending on how Draco feels about her.
At first, Harry could be heartbroken. He would wonder what he did wrong to make them leave. He might try to find them and reason with them. However, if he can't reach them, he would likely turn that pain into a driving force. He would focus on his goals, like fighting against Voldemort or protecting the wizarding world, even more fiercely, because he now has to prove himself not only to the world but also to his former friends.