Stopping Tamoxifen (again)

I had been on Evista for 9 years and then my onocologist switched me to tamoxifin, I started spotting and have been since Sept. 2009. I stopped all cancer pills cold turkey, I had a biopsy, pap smear and ultra sound (said uterus was thick, that's why I had biopsy) but everything came back normal and I am still spotting.  How are you suppose to feel when you get estrogen back in your system, could this cause the spotting?  I have asked onocologist and gyn and they keep referring back and forth to one another, like no one knows if the spotting is normal or not.   If you could please answer this, I would be most grateful, I don't know who else to ask.