This novel shouldn't be an arc in a QT. Basically, the MC transmigrates and goes into the rich spoiled second-generation young master. There's this guy who wants to kill him when he transmigrates but then he accidentally swallowed a red bead that belongs to ML. This should be an apocalypse theme novel. Suddenly his belly starts swelling up and then they go to the hospital and apparently he's 3 months pregnant. And the ML wants to kill the young master but doesn't know it's the MC.
Probably this: "[BL] First Corpse Wife [Di Yi Shi Qi]" by PurpleLove666 on Wattpad Its a pity PurpleLove666 has yet to upload their translations of various novels here despite being a wonderful translator. (I have asked but messages goes unanswered so maybe they don't like NU complex upload scheme?) Edit: apparently it's the same novel as the above just translated into a different title.