Looking for advice

I was previously a single mom and I will soon be married to my fiancé. I have 1 child who is one year old. The topic of having children has come up and I am a planner. He wants a child immediately after marriage, however I do not think that is the best idea. We looked at our finances and my income can support myself and my son (obviously) but his income cannot support another child in the picture. If he were to get his bonus EVERY MONTH then he would help afford a second child. If we were too have another child then he would either have to make more money or stay at home (because I’m not doing that) and he would still need a parttime job to help ends meet

My main focus is paying off some things first to free up some monthly payments taking up our budget. How do I have this conversation with him?

Anyone else in a similar situation and what did you do?

Note: He is highly emotional and desperately wanting a child of his own. Growing up adopted he had no one who was biologically related.