Which novels described the female protagonist using the male protagonist as a substitute?

I recommend 'The Substitute Wife: Mr. He, Please Sign for Divorce' to you. This novel was a modern romance novel. The female protagonist found out that she was only a substitute after five years of marriage, so she filed for divorce. The male lead had not completed his mission, so how could he agree? However, the female lead had already changed her boyfriend. Later, the female protagonist suddenly became pregnant. The male protagonist did not want her to be with anyone else, so he began to protect the female protagonist like a madman. I hope you like my recommendation.😗