Epic story of Unfaithfulness

I have a boyfriend that I met around two years ago, everything was going perfectly fine until recently about a month or two ago, I found out that he got a girl pregnant and that she was six months at the time so she's like eight months now. The funny thing is he wants us to try for a baby but I'm not sure if that's like a good idea. He's like only doing it because he doesn't want me to leave him, like what should I do? I don't mind having a baby at all, I actually want one but do you guys think I should try with him? because originally, I was just going to leave him and try with someone else, but he doesn't want me to leave him, so I don't know? I mean we have already been having sex ever since my period went away, Although the app says my ovulation is later on this week. What should I do?