Can Polycystic Ovaries Cause Prolonged Period?

hi my name is krystle sylvester from trinidad and tobago. my problem deals with my menstrual cycle. since i started at the age of 11 i have had prolonged periods, lasting between 2weeks-3months. i have visited different doctors and they told me i have polycystic ovaries and had me taking birth control pills such as nordette, yasmin, alesse, among others. i am now 23 years old and i still have not gotten a proper answer or explanation for my demise. could u please help me. i am also trying to concieve to no avail.