Unfortunately God's designed men to be able to easily make families later in life; not so for women.
And as stated in many of the other posts, I have seen dozens of my friends shocked to learn at 35 or 40 years old, that they could not have children. It is heart rending. And for many folks adopting is not an option; they don't have it in them. Fact of life, sad but true.
I know too many people that will be able to spend their last 40 years with plenty of money and nothing but regrets for the way they spent their life between 22 and 35.