Mazal tov on your upcoming wedding!

Mirena in particular has a tendency to cause unpredictable spotting for a long duration.  Spotting can sometime continue off and on for six months.  On the other hand, once the body adjusts, a woman on Mirena may cease all bleeding for years.

Since Mirena itself secretes progesterone, it is not clear that taking progesterone will be effective in helping to avoid a chupat niddah, although you can discuss your options with your physician.  You are correct that choosing Mirena will make setting a wedding date less certain.

If you have not already done so, you may wish to consider other forms of contraception.  We list many of the relevant options in the “Family Planning” section of our site and are happy to provide further assistance.  Your physician should also be consulted.

If you do choose to use Mirena, we highly recommend reviewing the laws of stains, as by reading our site’s articles “Ketamim” and “Toilet Paper.” Before counting your shivah neki’im before the wedding, you should ask a specific halachic question about how to proceed and how many bedikot to perform. If you do encounter problems during your shivah neki’im, please don’t hesitate to ask halachic questions as often as necessary.

Please feel free to get back to us with any further questions.