Does Thick Uterine Lining Leads To Uterine Cancer?

I was recently dx with a thick uterine lining. (25) I started bleeding on Monday with cramping. I am scheduled for D&C soon. I was Dx with invasive ductal Ca estrogen +, Her2 +, progesterone neg. with 2+ nodes 4 years ago. I did complete chemo did not have radiation. Started Tamoxifen after treatment. My last period was 2-2010 until Monday. What are my chances of this being uterine cancer? Everything I have found is pointing that way.