I guess you are looking for the book " Flower of the Two Worlds of Yin and Yang ". The female protagonist is called Qing Wan, and the male protagonist is called Qiu Yuxin. It is a fantasy romance novel, which tells the story of the female protagonist who can travel between the two worlds of Yin and Yang after transmigrating. It also involves the plot of the male protagonist being a doctor. If you are interested in this book, you can read it. I hope you like my recommendation.