What happens if it doesn't work?

I have such a supportive group of family and friends and for that I am very grateful. But the question remains, what if we can't have children? I know there is always adoption, but the chances of us adopting are pretty slim (since we are both older).

My parents left us a message on our wedding video during the "interviews" that they want us to have lots of babies. But, what happens if we can't have babies? I know my mom is being supportive and optimistic by saying that we can always adopt if I can't biologically have a child, but she has never said to me, it's OK if you can't. We'll still love you. A part of me feels like this is just adding to the "pressure" of having children.

And, I'm not trying so hard to have a child just to please her. I want a child so MH and I can pass along our values, strengths, humor, life lessons, etc. to that child. I want our lineage to carry on. MH is such a wonderful caring man, that it would be a shame to not have that carry on.

What happens if it doesn't work? I hope to not have to find out the answer to this, but until I get a positive pregnancy test and STAY pregnant, this question is always on my mind.