New baby

So me and my current boyfriend have been together for a year but I met him going on 2 years ago. After the first 3 months of in the getting to know each other stage we end up breaking up because of an altercation we had. We ended up back together but a couple months later I found out he got the mother of his children pregnant. He claims it was a mistake and they'll never be together but it just happened. In today's time he's changed so much since then and I know he loves me but the new baby is here and 3 months old. Am I stupid for staying? Should I move on?