@Fo1wS Nah, for me it started when Ai die. From the start the protagonist is not Ai but the doctor anyway so when Ai steal the spotlight in baby arc, it feel like the author is gonna make Ai only as the back story, not the real one.
I doubt that Ai's children's parent being a creepy old men of the industry unless she were raped and that doesn't seem to be the case. I think the father may be a son of someone really important in the industry or someone marry.