To conceive or not to conceive

I am a nurse on night shift, 7pm to 7am. I have a 3 year old and a 14 year old. My husband works 9-5 during the day so he spends more time with our girls than I do. The agreement was that we where to start trying for a third child after I finished nursi school. That was a year ago, now my husband says he doesn't want to have another one until I am home more. I understand I work a lot of ours with overtime, but our income covers the bills. Less work = less budget for the house. I understand his point but I don't think he understands mines. I was looking for outside opinions. 😕