He got her pregnant.

I have been with my boyfriend for a year now, we were both trying for a baby ever since October. Lately my intuition kept telling me that something wasn't right. He would always be mad at me and I'd feel like I was crazy. Last night I sat him down and we talked..he confessed that he got his best girl friend pregnant and that they're both happy and excited. Meanwhile she has a boyfriend herself. He expected me to stay with him but I walked away. Now I'm left feeling alone and betrayed. How do I cope with this? How do I go on?