Could Irregular Menstruation Be Due To PCOs?

I am 23yrs old..I had irregular period after USG it found that I have PCO.. doctor gave me a medicine named CRISANTA but it dose not suit on me., vomiting tendency and trouble found. So doctor again suggested me to take a medicine called YASMIN .. It also creating same problem so I stopped taking the medicine after 8days... But now I am facing again irregular period problem... Last month date was 19th Feb 15 but in this month there is no menstruetion yet... How will I get reduced from this problem n a regularl period . pls suggest me doctor.....