Question about periods on the pill

Does any amount of bleeding on the placebo week count as a period, which generally means you’re not pregnant? I understand a period on bc is actually a with-drawl to hormones, but in regards to the length of bleeding and the amount of blood, weather it be only enough to fill a panty liner or a heavy flow; does any amount of blood on the placebo week mean you’re not pregnant?

** the last time i had sex, which was protected from my bc, was a month and a half ago, so pregnancy isn’t a concern, but generally asking for future months**