Kagome would most likely be very angry. After all, being kidnapped against her will is a huge violation. She would probably yell at Sesshomaru and demand to be released immediately.
At first, Kagome is likely to be angry. She's a strong - willed character, so being kidnapped goes against her nature. She would probably struggle and try to escape immediately, yelling at Koga about how wrong his actions are.
A jealous rival of Inuyasha might kidnap Kagome. For example, another demon who wants Inuyasha for himself might think that by taking Kagome, he can get Inuyasha to do his bidding. This would create a lot of drama and conflict between Inuyasha and the kidnapper.
One possible plot could be that Kagome is kidnapped by a powerful demon who wants to use her spiritual powers for his own evil deeds. Her friends then embark on a dangerous journey to rescue her. They face various challenges and battles along the way.
One common plot twist could be that Koga actually kidnapped Kagome to protect her from a greater threat. Maybe there's a powerful demon that's after Kagome, and Koga, despite his rough ways, believes he can keep her safe. Another twist might be that Kagome discovers she has some hidden power while in Koga's captivity that helps her either escape or gain an understanding of the demon world in a new way.
Another scenario could be that Sesshomaru gradually realizes that kidnapping Kagome to mate was a wrong move. As he spends time with her, he sees her kindness and intelligence, and he starts to develop a different kind of respect for her, rather than just seeing her as a potential mate. So he might let her go in the end.
One idea could be that their relationship starts as an unexpected alliance against a common enemy. As they spend more time together, they gradually develop feelings. When Kagome discovers she's pregnant, it could bring a new level of complexity to their relationship. Sesshomaru, being a proud demon, might initially struggle with the idea of impending fatherhood but then grow into a protective and loving partner.
Kagome would most likely be very angry at first. She's used to being in control of her own life and suddenly being kidnapped by Sesshomaru would be a huge violation. She might try to use her spiritual powers to fight back or at least escape.
Some great Inuyasha and Kagome fanfictions include those that focus on their adventures after the end of the series. For example, 'A New Beginning' which shows them building their life together in the feudal era. It has really good character development and stays true to their personalities.
In fanfiction, a Sesshomaru and Kagome pregnancy can be a very interesting plot. It often brings new elements to their relationship. Writers might explore how they handle the upcoming parenthood, considering their different personalities and backgrounds. Sesshomaru, being a powerful demon, and Kagome, a strong - willed human girl, would face unique challenges and joys during this time.