Husbands ready..but not me

Balee • Pastry chef, wife, and mother of a beautiful 3 year old!
My hubby is all ready to start trying for baby #2. My first is only 18 months so I don't really want another just yet. I'm up for a promotion at work in a few months. He just looks so sad everytime I start my period. It's kind of breaking my heart. What can I say to help him hold off a bit longer?