Having played her schemes, Wu Ningjing had forced Luo Xusheng into a relationship with her, and when his anger exploded, she sought revenge by sleeping with Li Tianguang, who later became her husband. Nonetheless, Wu Ningjing was fairly certain that Luo Yuqing was indeed Luo Xusheng's daughter.
At the time she had sex with Luo Xusheng, she had carefully chosen the date—it was the day she was most likely to conceive.
Back then, her goal was to become pregnant with Luo Xusheng's flesh and blood to blackmail him.
When the blackmail effort failed and subsequently destroyed the last bit of goodwill Luo Xusheng had for her, leading to his intense disgust, Wu Ningjing lost her rationality.
However, when she was with Li Tianguang, several days had already passed.
Moreover, she did not let Li Tianguang's essence remain inside her.
Although there was still a possibility of pregnancy, the child she was carrying, Luo Yuqing, was most likely Luo Xusheng's offspring.