If Ginny were pregnant, their relationship would transform drastically. Snape would have to confront his feelings in a more profound way. He might become more protective of Ginny, but also struggle with his own insecurities. Ginny would depend on him more, and they would need to communicate better. For example, Snape might have to open up about his past to Ginny in order to build a stronger bond for the sake of the unborn child. Also, they would need to face the potential judgment of their friends and family. Harry, for instance, would be very shocked and might initially oppose their relationship.
It would become much more complex. Snape, who is usually a solitary and somewhat brooding character, would have to step up and be more involved. Ginny, being young and from a different generation, might expect different things from him. Their relationship would likely face a lot of external pressure from the wizarding community too.
A possible plot could be that Ginny is pregnant and Snape, as headmaster, is trying to keep it a secret from the wizarding community. He fears that if the news gets out, it could put Ginny and the baby in danger. So he arranges for Ginny to stay in a secluded part of Hogwarts. Meanwhile, Ginny is not happy about being cooped up and tries to find ways to still be involved in the wizarding world while protecting her unborn child. This creates a lot of tension and interesting interactions between Ginny and Snape.
Their relationship would likely become even more intimate. They are about to become parents, so there would be a new level of closeness. Harry would be more protective of Ginny, making sure she's comfortable and safe during her pregnancy.
One idea could be that Snape discovers Ginny is pregnant and he's initially in shock as it goes against all the norms of their relationship. He then decides to be there for her despite the potential scandal. Another could be Ginny trying to hide the pregnancy from the wizarding world for fear of how they'll react, especially given Snape's past and her own family's reputation.
There could be many interesting fanfictions on this topic. One idea could be that in this fanfiction, the 'force' might be some sort of magical or emotional force that binds Harry and Ginny even closer during her pregnancy. It could explore how they deal with the impending arrival of their baby while also facing challenges related to this special force.
Ginny may develop from a young, somewhat rebellious witch into a more understanding and empathetic person. The forced marriage situation might make her look beyond her initial impressions of Snape. Snape, too, could change. He might become less cold and more open to the idea of love and family. He may start to see Ginny not just as a student's sister but as an equal partner.
In this fanfiction, Ginny's pregnancy would bring about a whole new set of relationships and responsibilities within the Weasley family. The family would need to support Ginny not only during the pregnancy but also in her new role as a mother. There would be more family meetings and discussions about the baby. The younger Weasleys might look at Ginny differently, with a new sense of respect or perhaps some envy. And the family as a whole would have to deal with the outside world's reaction to Ginny's pregnancy, which could also affect their internal dynamics.
Her friends would be greatly affected. Some friends might be supportive at first, offering help and advice. But as the truth might start to surface, they could feel betrayed or angry. And if she has a romantic partner, that person would be one of the most affected. They could feel pressured, confused, or deceived depending on their relationship with Ginny.
On the other hand, sometimes the punishment can lead to an unexpected understanding. Snape might see Ginny's potential through her mistakes during the punishment process. For example, he could notice her determination when she has to complete a difficult task as punishment, and Ginny might also realize that Snape's strictness is not entirely without reason. This could gradually transform their relationship from one of animosity to a more complex, grudging respect.
They would become more protective of each other. With a baby in the picture, their love would be deeper as they are now a family. Harry, who has always been a bit of a lone hero, would be more cautious in his actions as he has a family to think about. Ginny, on the other hand, would be more nurturing towards Harry as well as the baby.
It could make their relationship more intense. Knowing he's going to die, they might cherish every moment together more. There would be a sense of urgency in their interactions.