My partner has stopped taking birth control (minerva) 6 days ago, and has started bleeding from her vagina last night (it is still persisting). we did have protected sex the night before if that is relevant. should we be concerned?

Early bleed w/o pill: The classic birth control pill comes in a package with 21 pills of one color (the ones to discourage ovulation and keeps the uterine lining thick), and 7 pills of another color (some people refer to them as "sugar pills") that either contain no medication or some progesterone, to allow (if no medication) or stimulate (if medication) uterine lining sloughing prior to preparing for the next cycle.