hi am 20 years old and been having very irregular periods. At times i dont get my perids for months and have to take contraceptive pills in order to get my period. I have not gotten my period for 6 months now and i a 100% sure i am not pregnant. I did have cycsts before. I do get extremely bad back pain and stomach pain. Sometimes the sides off my stomach and back gets tightned and pains really bad. I also feel bloated. At times i look all trim and slim and at times my stomach is huge. My back pains all the time, and i do get abdomenal pain. Can i have OVIRIAN CANCER ? I am really worried:'(