Any advice?!

So I’m 25 and my boyfriend will be 48 in October. We have been trying to get pregnant for a few months with no luck. He has two kids and I have one as well. When I tried for my child, it was literally the next month that I was late and found out I was pregnant. She is 1 now, so I know my body is basically regulated. I’m not saying that it’s going to happen immediately and I am still being very patient at this point. But he and his kids mom did have somewhat of a difficult time conceiving. He’s concerned that it’s his fault, but isn’t ready to go to the doctor over it just yet. Has anyone else experienced a similar situation? I would love to be able to ease his mind at least until his ready to go to the doctor if the time arises for that.