I recently purchased a mooncup (menstrual cup) online and the first month I used it I have discovered that for the first time ever (on a non pill cycle) that I can go to the mikvah on day 12 rather than the usual day 13 or 14. Anyway I e-mailed mooncup to tell them and they said that they had feedback from other people that the mooncup shortened the length of their periods. To me this is pretty exciting news for anyone who has a longer cycle and observes hilchot niddah especially for those who were having problems conceiving because they ovulated before they got to the mikvah.