Should I Continue Using Duphaston Or Switch To Diane 35 For Conceiving, Considering My PCOS Diagnosis?

I am not conceiving since one year of getting married. I am PCOS patient. I had used Duphaston for 3 months.. had dark stained periods for just one to two days. Now my doctor has advised me to use Diane 35 for 3 months. But i have listened that diane will prohibit the chance for conceiving so instead of Diane i should continue Duphaston. Plz suggest me which medicine will help me in conceiving?