How To Treat PCOS And Irregular Periods, No Improvement Despite Various Medicines?

hi... am 22 and unmarried. am suffering with polycystic ovaries 4 abt 2 yrs. my doctors prescribed me many medicines but all in vain. till now i have tried many tablets like ovarall, krimson, hyponid, metformin, m2 tone etc. still am not getiin my periods regularly. am 66 kg mow nd maitaining the same thru regular exercise.still am not gettin my periods periodically. pls do suggest me the right way to get rid of this problem