Marriage after menopause

Yes, but only prior to marriage. A woman who has menstruated in the past, however distant, and has not immersed, must undergo the process of becoming tehorah before marriage. There is also a halachic concern that a woman’s desire preceding marriage might lead to a special type of niddah bleeding. Therefore, you should perform a hefsek taharah a week before your immersion, count the seven clean days, with the attending bedikot, and then immerse in the mikveh, no more than four days before your wedding date. The articles on our site should help guide you through each of these stages.

This answer assumes that you are completely post-menopausal with no staining.  Please advise if this does not accurately describe your situation.