I recently started the pill and I'm confused about the last week of pills that you take (some are sugar pills, mine are iron pills). These pills aren't hormonal birth control. Do you have them once all of your pills are done with the intention of having a period? Or do you wait until you start your period to take them (start a new pack in the meantime)? Since I'm new to the pill my doctor said I should allow my body to have a period for at least the first 3 months, I just don't know when these placebo pills come into play. Help please?