Is it normal to bleed for 3 weeks after switching to a progesterone birth control? switched from lessina to norlyda because of high bp?

The most common side effects of progesterone birth control is breakthrough and irregular bleeding as the endometrium become atrophic and ulcerated. Breakthrough bleeding usually occurs when the progesterone to estrogen ratio is high which can occur with progesterone birth control.

The general rule is that any change in hormones can lead to irregular bleeding for 1 to 3 cycles, because of the effects on uterine lining. But if the bleeding becomes heavier or persists longer a Dr eval is needed. It is a frustrating thing but likely will be fine & discontinuing the estrogen should help lower your blood pressure & cardiovascular risk.