I have an ovarian cyst on my left side.i just started bleeding, period isent due for two weeks?what is this?

2 Things: It's possible, though unlikely, that the ovarian cyst caused your bleeding. Most cysts aren't hormonally 'active' as it were and wouldn't affect the uterus' cycling. More likely is that you are having breakthrough bleeding, due to changes in your ovaries' production of estrogen and progesterone. See a doctor if the breakthrough bleeding continues.