Can you recommend a novel about childhood sweethearts?

The male protagonist and the female protagonist were childhood sweethearts. It seemed that in high school, the male protagonist found a condom in the drawer of the dean and said to the female protagonist,"It's too much of a loss to give your first time to a man who has experienced hundreds of battles. You should find someone who is a virgin (roughly the meaning is this)." Then, the male and female leads did it, and the female lead became pregnant. Then, the female protagonist dropped out of school and lived with the male protagonist. The male protagonist pursued another woman during university, and the female protagonist even helped the male protagonist come up with ideas. The second female lead later found out and quarreled with the male lead. The male lead lost his temper at the female lead and pushed her. The female lead had a miscarriage…A few years later, they were still together. I read this book about 4 years ago, please tell me the name of this novel! Thank you!