Hi Andir,
I'm so glad you posted this as I have been having similar issues. I was pre-menopausal before chemo & had my last period just before I started chemo in June 2012. After chemo I went on to Tamoxifen for the next 2.5yrs and just a few months ago was switched to Arimidex, as my blood tests were consistently showing I had reached menopause. However, recently I had a "mini-period" (aches & pains & brief show of blood), which I mentioned to my oncologist at my last checkup a couple of weeks ago and she immediately switched me back to Tamoxifen, did a further blood test review (still showing I'm menopausal) and got me to have a pelvic ultrasound (internal & external), both of which showed no abnormalities (thank God!). So, I see my onc again in a couple of weeks to talk over the results but think she wants me back on Tamoxifen for the time being. Not sure if there's any other plan yet!
I can understand your worry and concern. These continual reminders and fears test us all but hopefully all will be well with you too - as you say, maybe it's just a system clear out after all the chemo etc :-) Best wishes, Jane xx