Marriage and Kids

I always thought I would want kids but lately I've changed my mind. My husband has a son already. I have none. He still wants but I don't. Is it wrong of me to expect him to forget about having more kids and to just be happy with one. I'm hurt because we only been married 5 months been together 5yrs. Would you divorce over this? I also have a fear that we will cheat and get somebody else pregnant if we stay together. He never cheated and he never gave me a reason to think so but my ex did it to me when I didn't want kids with him. Plus my husband wants kids so BADLY. 😢😢😢😢