What Causes Delay In My Periods?

I ve been having my menstruation for two month s(June&July) after missing it just for a month (May).My last normal period was 14/04/2014 . Well I went to the doctors on 15/08/2014 and the doctors prescribed me a couple of medicine. AMOXIL METRONIDAZOLE FEFOL NORENTHINDRONE &SUPRAYDYN I have been taking my doses on time but I have noticed that my eyes are yellowish, I m pissing dark yellow, having chest pains from time to time and dizziness.