It can be frustrating to be passionate about something and find your mate does not share your passion.
To allow for peace and harmony, you can either . . .
1. Sell him the idea gently over a period of time and hope he will eventually accept your proposition or
2. Forget the idea completely
Option 1 requires a lot of patience because it is often difficult to change people once they have their mind made up about something.
Option 2 is the way to go if your partner is obstinate. Besides, it's the easier option.
In your case, you're desperate to experience motherhood and your would be husband is not interested in having another child.
This means option 2 is not feasible for you. Option 1 seems to be the preferred option.
But option 1 is risky. How?
Having a child of your own is very important to you. If you go into the love relationship in the hopes that you may eventually convince him to change his mind, you may be disappointed and disillusioned if he doesn't.
Eventually, you may have to break up.
The rule of thumb in a love relationship is this: If you have a torny issue that you're unable to resolve during courtship, don't assume you will resolve it when you get married.
Instead, forget the relationship. If you don't, it could cause you more harm than good.
In summary, you have a third option: Don't go ahead with the love relationship if you're going to be stuck with this unhappy feeling being denied motherhood.
That sense of loss will ruin your joy and eventually ruin the relationship.