Hi RosieOscar
Provided you are taking the licensed dose of progesterone to balance the oestrogen dose, then lack of withdrawal bleed should not be a worry. It is abnormal, unscheduled bleeding which can be a cause for concern.
You don't need to go back to the GP to report lack of bleeding, unless you have other symptoms that are concerning. Are you taking the progesterone orally? That is the only issue, whether you are absorbing it, though it would be unusual not to unless you have some sort of gut condition maybe that upsets your digestion?
Glad your symptoms have improved! It is important that you stay on at least a medium dose of oestrogen until the avergae age of natural menopause (51/52) due to your likely early menopause, in order to protect your bones and heart.
Hurdity x