HER2 Support Group Forums - Tamoxifen and regular menstrual cycle

I am ER+ PR + and HER2+.
I was diagnosed in Dec 2005. I completed Herceptin in June of 2007.
I started Tamoxifen in June of 2006. I am pre menopausal.
I started regular periods in January of this year.
Has this happened to any one else?
My surgeon says I need to discuss this with my ONC as I should not be having a regular menstrual cycle.
Options are to have the Ovaries removed or take lupron shots monthly
My BIGGEST concern is losing my sex drive. I have a great sex drive; I am 49 and wish to continue to have great sex.
What do I do?