I think i have an ovarian cyst. after sex i had some light bleeding, is that a symptom?

Not likely the cause: Typically ovarian cysts don't cause bleeding unnless they rupture or get twisted onto their own tubes etc...Light bleeding after sex is quite common for those having a male partner who is a bit on the long-side--repetitious trauma of the penis pushing/thrushing on the cervix which can bleed a bit. If u have some cervical polyps, fibroids, infections, cancer, bleeding is even more common. Good luck.