I recommend the book " The 999th Day After Breaking Up with the CEO " to you. The plot is very similar to what you described. The male protagonist was a doctor. After the female protagonist and the male protagonist broke up peacefully, they found out that they were pregnant. The female protagonist gave birth to the child. Many years later, when the two of them reunited, the male lead was still insisting on pursuing the female lead. I hope you will like this novel.