Hi Sunnydays
Sorry your post seems to have got missed - this board doesn't get visited as much as All Things Menopause and New Members. Those are the only two boards I visit if in a hurry and sometimes only one of them when I'm v busy as recently!
Anyway your question.....it is quite normal to start the withdrawal bleed any time from towards the end of the progestogen phase of HRT through to a couple of days following withdrawal of the prog. Are you post-menopausal - I seem to think so? I would have thought that taking a progestogen orally will potentially cause more variability in actual systemic levels as it is subject to the vagaries of your digestive system? It could also mean that your womb lining is more ready to shed and could be thickening more than it should - but you are having scans so that's OK. If you are worried about an early bleed then your doc should be able to arrange a scan on NHS - but this needs to be done immediately following the bleed so the lining is at its thinnest.
In terms of whether to finish the course - personally I always would as even if you have started to bleed, the progestogen is still doing its job. If you want to try a shorter cycle then you would need to have a scan after a few months. However you could always experiment and just stop the prog when your bleed starts and count that as day 1 - and then see when you bleed the next month or few?
Anyway - it does sound like you are not bleeding at the "wrong" time, nor that it is heavy or prolonged so I wouldn't worry unduly
Hope you haven't written us all off because no-one replied?!
Hurdity x