Your wedding celebrates the new life that you and your intended will begin. You aspire to prosper together, perhaps have children or blend existing families, and stay together forever. How does a prenuptial agreement or premarital agreement fit into those plans? If you suggest having one, aren't you telling your soon-to-be spouse that you do not think the marriage will last? In short, no.
When does the divorce process begin? Does it begin when you or your spouse first start talking about it? Does it begin with the filing of a complaint for divorce?