Oh goodness....that thing about being miserable without kids at age 50 is a bunch of horse poop. I have friends who are over 50, have kids, and are always stressed out. The kids are grown and out of the house, and yet they are still major pains in the neck. I am happy to be childfree at almost 45, thank you very much.
It is an individual choice, one I am happy I made, and my friends I referenced above tell me that I made the right choice. Some women just have kids because they feel it is what they are supposed to do, but later they regret it because they did not take the time to really make the right choice for themselves. Whichever way you go it should be your choice and yours alone, not influenced by anybody else.