Which novel told the story of a woman disguised as a man who hid the chastity sand under her feet and replaced someone else to become the heir?

I recommend "The Concubine is Often Powerful: First Grade Crown Princess". This novel tells the story of the female protagonist who accidentally became the Crown Princess after transmigrating. In order to prevent the prince from cuckolding her, she was left with a cuckold. At the same time, she had to deal with a scheming man who was good at pretending to be a pig to eat a tiger. I hope you like this fairy's recommendation. Muah ~😗