I think the legal details of this will need to be worked out but this is certainly very interesting! In theory, such a move ought to make you a more desirable wife and ought to prevent certain types of mistrust in the hypothetical husband. I doubt both of these would pan out in practice though, unless you are fairly certain to restrict your pool of potential husbands to the ultra-rationalists (who probably barely even exist in practice), or to guys who would a priori have preferred paternity testing, even before you bring it up to them.