Partner doesn’t want baby 😢

We’ve been together nearly 4 years & I found out yesterday I was pregnant again & told my other half.It was a shock to both of us,as we weren’t trying,but we were going discuss whether we wanted another 1 at Christmas.He’s now said he doesn’t want anymore children.I don’t know what to do & would love another baby,but how can I have it knowing he doesn’t want it?He’s 40 & said he’s too old,although I’m only 35 & he didn’t do anything with our other one,who’s nearly 2.Has anyone else been in this situation?I hate the thought of any baby being unwanted,especially when a lot of people want children and cant have them.