You don't say how old you are, which may have an impact. I was 44 at diagnosis in 2007, periods stopped on chemo a few months later and stayed away for five years of tamoxifen. I assumed I was menopausal. Three months after stopping tamoxifen, at the age of 50, my periods returned. I had 4 periods over the next 12 months then they stopped, although my hormones were still clearly at work as spots were coming and going every month even if there was no period.