Vitex? How long did you take it before your late period started?

Anyone taken vitex to start a missing period or to regulate them? How long did you take it for your period to start? My period is 18 days late with bfns and I started taking vitex on the 14th of this month. So today will make 12 days of me taking it and I still haven't gotten my period. I've been taking 2 capsules in the morning and 1 at night. I've been having nothing but creamy/milky discharge, a twiching feeling in my lower abdomen