Should prenups include assets acquired during a marriage?

When I signed a prenup 16 years ago, I thought it was for assets acquired prior to the marriage. A couple of years ago, I realized it was for everything during the marriage as well. My husband and I have always had separate accounts and now we are divorcing. In that 16 years, I have made about 1/20th of what he has made and he believes that I should walk away with nothing. Do you think this is right?