You start the next month's medication a few days earlier on the day that you want to change to. Having a shorter pill-free, patch-free, or ring-free week will not change the effectiveness of the...
no, when you get the shot it takes 24 hours to become effective in your body. after that, you are protected from pregnancy for 13 weeks till you are due for your next shot.
When you get to the inactive pills, take one per day until you reach the new day you wish to use - toss the remainder of inactive pills the day you begin the next new packet.