Hi, 

I have been on Zoladex and Anastrozole for 3 years, I started this at 36 due to breast cancer. After 5 years so in 2 and a half years time I will be taken off this and put on Tamoxifen. I was informed of this at my recent oncology appointment. 

They did say I would be checked to see if I am in menopause before I start the Tamoxifen. I will be 41 by this point. I am just wondering how this is usually tested? I’m assuming I can’t have a blood test when I’m still on Zoladex and anastrozole. 
Just curious how estrogen production is assessed?

Thank you