Hi Rolly
If you have had a blood test which tells you that you are post menopausal then it means your body no longer produces enough hormones to make eggs so pregnancy is impossible (I am lead to believe!).There is a really good book called breast cancer and early menopause from the National Breast and Ovarian Cancer Centre which has lots of really useful info about menopause and what to expect I dive into it quite regularly.
I am 52 and on tamoxifen I am not "truly" menopausal yet but they'll test me in 2 years to see and then change my tablets.
Good luck
Sarah x