Harmonal acne. Or 2nd day of the period.

Hi... i am having harmonal acne 2nd time from last 2 years... last time after trying so many anti acne products and medicines my dermatologist put me on ginette 35 within few months my skin got clear... but again from last month i am having same breakouts... i didnt get my blood test done yet but i am 100% sure this is not a normal breakouts as they are big cystic painful pimples or acne... right now i am taking tretiva 20 mg but its not working my period will start on 11th or 12th of oct but i am scared till then my skin would get worst.. my question is should i start taking contraceptive pills before my periods though i know it should start from 1st or 2nd day of the period. Please guide me my skin is getting worse day by day.