What is breakthrough bleeding? Does it mean I'm pregnant? How long can I expect it to last? 8days after my normal cycle and bleeding for the 2nd time!

Breakthrough bleed. Breakthrough bleeding which is when you have bleeding at unscheduled times while on birth control. Often things get back to normal the next cycle. If not then schedule a visit to discuss changing brands or changing birth control methods. This is very common. Other than being annoying it is not dangerous. Pregnancy tests would work just fine and you can take one if concerned.