Suggest Remedy For Delay In Periods

I have a PCOS, my OB advised me to take Yasmin for 3 months. After 3 months I get back to my OB then she said I still have to take Yasmin for another 6 months together with Metformin.My last period was January 24. After my check up she prescribed me to take Duphaston 10mg twice a day for 5 days. She want an early bleeding so that I can start taking Yasmin and Metformin. Until now my period doesn't come, it's been 12 days after finishing the last tablet. Thanks!