Vague Dr's Visit

I am 49 and pre-menapausual with a 3.6 reading last year which was very low I am told.  My annual pap smear came back Atypical Glandular Cells and the Dr. called me back in for a biopsy. She performed a colposcopy, endometrial biopsy and endocervical curetting and the results were all negative. The doctor is asking that I return for an ultrasound so that she may take a look at the thickness of my uterine lining. I do have fibroid cystic activity that makes it challenging to get a good read. Should this make me concerned about the validity of the ultrasound test?

I have had an endometrial ablation six years ago and she is concerned that serious symptoms could be masked if they were to be presenting under normal circumstances. Furthermore, I am to return for another pap smear in 4 months.

Based on the abalation, is there anything else you would suggest with this AGC being present in the pap results?