Hi.I'm 35 yrs old and having pcos.I have very painful and heavy periods and irregular cycles as well. I'm takin duphaston 10 mg twice a day from day 5 of my period till day 21st since 2 months.I have had only some black spotting after taking this medication before 21st day and no actual period.im not pregnant for sure.should I continue this medication during this time and consider this as a irregular cycle and start from day 5 till day 21 again as I have been asked to take this for 3 months to correct my irregular period.