We also,had no number in mind when we talked having kids

After number 1 I didn't want to do it again. It took dh 18 months to convince me. Me decided to stop at 3 but I had that urge and it took me a yr to convince dh 4 is a nice number. Very much done now.

Maybe talk and give reasons as to why you want another (and yes just wanting another is a valid reason). And listen to your dh as well. He may think 3 is a little to much to take on.