Generally speaking it can take 3-6 months for bleeding to settle if it is going to.
However what can happen in perimenopause when women use sequential hormone therapy, is they end up having both the iatrogenic withdrawal bleeding AND menstrual bleeding.
Contrary to popular belief these don't always overlap.
This can result in unpredictable bleeding and more days spent bleeding overall than untreated women.
This is a nuisance not an illness, and one that many women just put up with - it will eventually stop when you reach menopause - you will then just be having the withdrawal bleeds unless and until you switch to continuous progestogen.
However nobody at any stage has to bleed at all unless they want to, and there are multiple bleed free alternatives that you could discuss with your GP.