I had breast cancer 2/14. Stopped having periods when I started chemo 4/14. Started on Tamoxifen 4/15. Developed pulmonary embolism 9/16 due to Tamoxifen and started on blood thinner. I had a little bit of spotting over the last year, but very light. Started on Arimidex in October. Doctor concerned about spotting so I had a vaginal ultrasound. Showed thickening of uterine lining 1.7mm. Started a rather heavy period on 2/2. Is it possible that I am not through menopause yet? I am 53.