Hi again,
I just took a look under "HRT preparations: for postmenopause" (on this website) and cut and pasted the bit about just what you asked:
"Period free" or continuous combined therapy can be used by women who are 54 + yrs, or more than one year since last period at any age. The criteria should be fulfilled in order to offer such treatment to women who no longer have a continuing ovarian cycle, so that steady levels of both estrogen and progestogen can be achieved. When there are steady levels of estrogen and progestogen from daily administration of both, the womb lining stays thin. Although some bleeding in the first 6 months of therapy is common, there should not be bleeding after that and the lining does not go through the stages of stimulation and then shedding as it does during a normal cycle and with sequential therapy."
So next stop: GP - best of luck.