Can simple ovarian cyst 3.8 mm cause a very heavy period? I'm soaking through pads every hour w/ severe cramping 9 days. I also have an enlarged uterus

Uterus not ovary. The enlarged uterus is the more likely source of the 9 days of heavy bleeding from fibroids or other growths rather than the ovary. Have a GYN MD investigate that issue more thoroughly.