No there should not be continuous gradual shedding on conti HRT once it has settled. This is not how it works. What happenes is that eventually the progestogen interferes with the oestrogen receptors in the uterus somehow, to prevent the lining growing under the influence of oestrogen. If there is bleeding after a long time even if only slight then this is abnormal. That being said, if the bleeding you had before was partly due to the build up of lining, then changing to conti could cause gradual shedding until the lining thinned down. However if you've had a scan and all is well, and the lining is thin then who knows?!
Any bleeding/spotting should settle after 6 months but that is average and in some women it may take longer.
As Donna says if you are still peri then you will continue to get bleeding/spotting. OK you used to get signs of ovulation but maybe these are not so apparent once on HRT? At 44 you are more likely, on average, still to be peri unless you are experiencing an early menopause, which of course does happen! If ovulation only happens rarely though, it would be unlikely to cause continuous staining I wouldn't have thought, but a breakthrough bleed now and again....
What was the thickness of the lining when you had the examination, as that is also an important measure of likelihood of bleeding/spotting?
Hurdity x