What does it mean when a guy randomly uses a condom?

I had been dating a guy for a month. Whenever we have had sex, I would be the one to use the birth control. However, today when we were finally going to have sex, he introduced using a condom. I didn’t say anything about it because I was too stunned to say anything. I just agreed. So we had sex. After, he said we don’t have to use condoms anymore. So I’m wondering what it meant when he randomly used a condom. Did he want to break up with me? Or was he just being cautious? Please help me understand the reason why this happened!