Normal results ever wrong?

I'm having surgery later this month to remove an ovary due to awful symptoms. They've been persistent for about 8 months now. The ultrasound showed my ovary has cysts, but nothing else concerning. Has anyone had a normal ultrasound but it turned out to be ovarian cancer?

I'm having bloating, abdominal pain, change in bowel habits (I used to be VERY regular, now I'm going every 2-3 days, and it's usually loose, no diet changes), extreme fatigue. I had a partial hysterectomy almost 10 years ago so no periods to help determine other symptoms. Obviously I won't know what's going on until after surgery, just wanted to talk to others.

Thanks in advance ☺️