21 and afraid

I'm 21. I just found out I'm pregnant today. I was told by many many doctors that I'm infertile. I was married for 2 years and tried every month to conceive, nothing. A year after my divorce I met my current boyfriend. We've only been dating and living together for 2 1/2 months. When I told him today he was scared at first but now he's so excited, I'd say even happy. But my live feels like it's over. We both have steady jobs and together make over 100k a year. So money isn't a problem. But we've only been dating 2 1/2 MONTHS! I'm so scared. He swears he will never leave. But I doubt we will get married. We don't even say I love you yet but I do know I love him. I'm just so afraid. What do I do? This is literally a miracle child.