Blister packs with 21 pills contain the amount of Microgynon you need to take in a month, with a 7-day pill-free break. The blister pack with 28 pills contains 7 placebo pills. These pills don’t have any medication in them, so it’s just like taking a 7-day break. You may want to use this to remember to take your pill every day. This can be helpful if you forget when to start taking your pills after your break.