It's Been More Than A Week Since I Took Meprate

It's been more than a week since I took meprate thrice a day for 4 days, I still haven't got my period. How long does it usually take? When will I get it? What should I do? I have PCOS condition so my gynec suggested I take this and do further tests on the third day of my period. Also I'm trying to get pregnant, so she prescribed me melmet and folibest in addition.