Want to TTC but...

I don't know if this is the correct group to post in, but I will anyways. I have had baby fever for the past 6 months. My son will be 4 in February, and my husband doesn't want another child, at least for a while. I feel as though if my son hits 5 before we have another one, I don't think I want another one. I had always wanted my children to be closer in age, if I had any. My sister and I are 15 years apart, and my husband and his brother are 4 years apart. My husband has always said that he hated how far apart in age they were, but doesn't see that for our son. Before he changed his mind, he said he didn't want another. That completely crushed me, and had me bawling for a long time when I was alone. I don't know how to bring up another child without upsetting him now, but I feel like the window, at least for us, is closing because of the age gap between children. I only say that because he has said he doesn't want another if my son is 5 before we conceive again. I just need someone to talk to, but all of my friends are not married and do not have children. I wouldn't get pregnant purposefully, but I want another baby...