Plan B/Birth Control questions!!

Caitlyn

1. How long does the Plan B pill stay in your system?

2. Do you think the activated charcoal could have affected either the Plan B pill or my birth control even though I took the actived charcoal many hours after I took either pill? (AC gets the toxins out of your body, i took it bc i was hungover)

3. Can you take Plan B even if you are on the pill? ( I took it during the placebo pill week)