How Concerned Should I Be About The Uterine Thickness And Bleeding A Year And A Half Post-menopause?

Hello, I am 18 mos post menopause. I am 49 yrs old. I bled for a week and my dr ordered a trans vaginal ultrasound which showed my uterus thickness at 6mm. I now have a hysteroscopy with d and c scheduled. How worried should I be? My pap came back normal. What are the chances this is cancer and if so, is the bleeding an early sign or more advanced symptom?