One popular Blair Waldorf pregnant fanfic might be 'A New Chapter for Blair'. It could explore how her pregnancy changes her relationships within the Upper East Side clique. Another could be 'Blair's Maternity Journey' which might focus on her personal growth during pregnancy.
You can try fanfic websites like Archive of Our Own (AO3). It has a large collection of fanfics from various fandoms, and there's a good chance you'll find Blair Waldorf pregnant fanfics there.
Well, Serena would probably be over the moon. She's always been close to both Dan and Blair and would see this as a wonderful union. She'd be there for Blair during the pregnancy, helping her with shopping for baby clothes and giving her advice. Nate, on the other hand, would be more practical. He'd offer to help Dan with any financial or housing arrangements they need to make for the baby. And then there are the more catty friends, like Penelope and Hazel, who might be jealous and make snide remarks about how Dan and Blair got pregnant so quickly, but deep down they're just envious of their relationship.
One great fanfiction could be 'Chuck and Blair's New Beginning'. In it, they face the challenges of pregnancy with their usual charm and tenacity. It shows how they grow together and prepare for parenthood, all while dealing with the Upper East Side drama.
Many fanfictions explore their relationship by putting them in new situations. When Blair is pregnant, they might have to deal with public scrutiny. This forces them to communicate better and support each other. Their love, which was often tumultuous in the show, becomes more stable as they face this new chapter together. They start to understand each other's fears and hopes more clearly, like how Chuck may be afraid of being like his father but Blair gives him the confidence to be a better man.
It's not appropriate. Fan - created works should focus on positive aspects like character development, new storylines within the realm of propriety. Sexual fanfics are not in line with these principles and can cause discomfort to many people.