broody

I have a little girl who is going to be 2 next week and my partner has a little boy from a previous relationship who will be 3 in October. I am so broody and want another baby so bad but he says he isn't ready for another until a few years. I really don't want to have to wait a few years because I've always said I want my kids ages to be close together. Is there any way I can change his mind? I do respect his decision and will never force him into anything he doesn't want but it's getting to the point where I cry over it so much because I want it badly. help please :(