Whose child is Zhang Chengcheng pregnant in Anjia TV series?

In episode 41, Zhang Chengcheng gave birth to his youngest son, Fang, to show his love for him.

"Feng suddenly went to the fine art shop to find Xu Wenchang. He said that he took a fancy to a farmhouse in Chongming and wanted Xu Wenchang to help him see the house. Xu Wenchang unplugged the charging cable of his mobile phone and left with Mr. Feng in a hurry. At this point, Zhang Chengcheng cried and shouted Xu Wenchang's name in the delivery room of the hospital. Zhang Chengcheng immediately contacted Xu Wenchang with his girlfriend Tingting, but Xu Wenchang's phone has been disconnected.

Tingting finally got in touch with Xu Wenchang. Xu Wenchang thought that the baby might be his own, but he couldn't help flying back to the city. Soon, Zhang Chengcheng successfully gave birth to a son. Tingting tentatively asked Zhang Chengcheng with the child's physical examination form. What is Xiaotian's blood type? Zhang Chengcheng said that Xiaotian had type B blood. Tingting's face suddenly changed, because the child's blood type is also type B, and it is impossible for Zhang Chengcheng and Xu Wenchang's blood type to give birth to a child with type B blood.

Zhang Chengcheng's last point almost failed, and she painfully asked Tingting to contact Little Tian Tian immediately. Xiaotian rushed to the hospital panting. Tingting told him the story of her child, and Xiaotian was dumbfounded. Xu Wenchang also rushed to the hospital soon. When he saw Xiaotian staying with the baby every day, he suddenly understood. Xu Wenchang calmly took out the prepared red envelope and handed it to Zhang Chengcheng. Zhang Chengcheng didn't face Xu Wenchang, and this time they were never involved. "