I need advice! Fiancee wants baby but......

A little backstory: My fiancee and I are buying our first house and getting married soon. Lately he's been more adamant about wanting a baby. We've been not trying but not preventing for a few years now. I had a second trimester miscarriage last year, it broke my heart. Before I lost the baby I really wanted children and was ecstatic about having one but ever since I just don't anymore. I honestly don't know why. I also have bad fertility problems and in the past this hasn't bothered him but I'm scared it will now since he really wants a family and to start ttc/fertility treatments. I want him to be happy, I know he'll make a great dad and I don't want to hold him back from that.

In need of advice please!