hey guys! it’s been a 6th day of breakthrough bleeding/“periods”.. and theyve started 4 days before my placebo pills, and, currently, im on my 2nd placebo pill. and im still bleeding (not even spotting), and i still have lower-back pain.. when i should expect breakthrough bleeding to end? when i will start a new pack? and is it even normal to bleed for 6 days straight? the amount of blood is not even decreasing with time.. (just for the info: i didn’t had sex for 2 months. and i’m on pill for 2 years)

It can anywhere from hours to multiple weeks. There's no way of knowing unfortunately. You're gonna have to wait it out. If you're currently on your break week, then most likely the bleeding will slow down once you start your new pack. Start your new pack whenever it's scheduled, regardless of bleeding pattern. Never extend your break as that will leave you unprotected.

^ this is correct. There isn’t much you can do. The bleeding is normal though, it’s not something to worry about.