When Will I Get My Normal Periods While Taking Daflon?

I have been taking meperate since the past 3 months for 21 days after which I take daflon for 7 days during which time I menstruate very heavily. I started the course of daflon and meperate immediately after my D&C for very heavy menstruation in Fbruary 2011. However this month during my menstrual cycle I have not bled at all even though my cycle date is on and also I am on daflon. Kindly advise as to how to calculate my menstrual cycle.