Beautifully written. You capture what I think Clark would feel when told he couldn't have children with Lois. However, it is my believe that they will have their own children. Doctors have been wrong about these sort of things in the past. I know of 2 different couples that were each told that they couldn't have their own children but they did.
One couple was told the wife had problems and wouldn't be able to conceive. They adopted a child and within a couple of months she got pregnant. Some very insensitive people asked if they were going to keep the adopted child. They were appalled that anyone would think they wouldn't.
In the other case it was a fertility problem of the husbands. They at some point got pregnant anyway.
In both cases there was so much whispered questioning about whether or not the children conceived were the couples natural children that both couple wound up having DNA tests to shut everyone up. A couple of friendships didn't servive.
So in my LnC world Dr. Klein was wrong and nature does find a way to give them children naturally.
Nicely done. 
First, I 
). It's such a brief moment, but it always breaks my heart just to even wonder what he's thinking or how he could be feeling at that moment when everything's *supposed* to be normal. 