I Have Had Ongoing Daily Vaginal Bleeding Since Mid September.

I have had ongoing daily vaginal bleeding since mid September. Before this I had regular 28 day periods. I have just turned 50 years old. I have had no pregnancies. I also have had no signs of menopause or peri menopause symptoms. I have insulin dependant diabetes (for 23 years) and I take thyroxine for an under active. My diabetes is, and has always been well controlled. I am normal weight and lead a fairly healthy life.
One of my doctors has said the vaginal bleeding I am experiencing is normal for my age.. My other doctor has said this could be due to a hormone imbalance (although no blood test has been done) but I am having an ultrasound scan this coming Thursday. In your opinion, what are the possible causes of my symptoms and should I prepare myself for a more serious diagnoses with the ultrasound this week. The waiting and continuos bleeding is causing me worry.. Many thanks. Rachel