I'm 90 years old and the system tells me it's time to create harem - Chapter 1: A system sixty years too late

When our protagonist becomes the game character Jun Karentia, she thinks she has it made. She may be just a lowly support mage, but with her knowledge of the game, she knows she can finagle her way to the good ending following around the main character, Fabian. The problem? This game doesn’t end after one playthrough. Jun is prepared to guide Fabian through the second playthrough to the true ending when… Fabian abandons her. Now the Grand Duke Mayer Knox—captain of the Dark Knights and the secret final boss—is determined to have her join his party. Can Jun turn the final boss into the main character? Why is Mayer Knox so intent on having her in his party? And when will these rumors about being his lover stop?!

Xue Xi is forced to fall in love at first sight with this dangerous man on their first meeting. With death being the only other option, she makes the first move:

[Urban Martial Arts, Passionate Martial World.] He was a super expert who, due to accepting an inheritance, underwent a physical transformation that put his life at risk. To extend his life, the king returned...

His filming opportunities were taken by others, his boyfriend cheated on him, he gave up a rich, tall handsome fiance and devoted himself to a scumbag. In the end, he was beaten to death by the scumbag. Yan Qing Chi felt that although this danmei cannon fodder supporting male that he transmigrated into was troublesome, it was kind of tragic that he died like this through his own actions.

So, the first thing that Yan Qing Chi did after taking over this body was to catch them in the act and beat up the scumbag! The second thing that he did, was to agree to the marriage proposal from the aristocratic fiance.

However, Yan Qing Chi stared down at his big belly. Who can tell him what the heck this was?! Don’t tell him that he transmigrated into a mpreg novel???

Standing on the side, tall, rich, and handsome Film Emperor Jiang asked carefully, “Babe, do you want a boy or a girl?”

Yan Qing Chi: Do I want a WHAT?!

- Description from Novelupdates