I'm 49 years old. Have been on arimidex for about a year and a half. A couple of months ago i started my period. I thought it was a flook and then the next month i started again, now month 3 is coming up. What should I do? I was diagnosed with breast cancer April 2006 estogen positive, her pos. 12 lymph nodes bad. Went thru chemo/ radiation /herceptin therapy.