I have my period but my blood is watery, really painful cramps that last long. All I could find out is ruptured ovarian cyst or miscarriage? Or pregnay

Watery period. If this is the first time this has happened, it may be. Pregnancy may be hard to prove if you miscarried because PT may be negative by now. Ovarian cysts may be shown on ultrasound, especially if you continue to have pain. Recommend birth control if you are not trying to get pregnant.