My husband wants a baby but I want to finish school

I have 1.5 years left so I'm asking my husband to wait. I even said we can start trying during my last semester or even towards the end of my second to last because I'll be done by the time the baby is born. He understands but sometimes he makes passive aggressive remarks about it that really hurts. I feel like I'm failing him. I feel selfish. It hasn't been a huge fight yet but I feel like it's eating us alive...I haven't told anyone because I feel like it's not their business, but not sharing is making it hard also.