I was suppose to get my period on 3/20/12 but I didn't. I waited until the next day, 3/21/12, and still no period. I was becoming a little paranoid and decided to start my birth control pill that day even though I hadn't started my period or waited until that Sunday. What will be the result of my decision?

It may just throw off your cycle at first. When you either stop taking pills for the last week, or take the placebo pills in that week, your period is supposed to occur at that time because of the change in hormone levels. Be sure to use a back-up method of birth control until you have your next period. Although it would actually be wise to use an additional method, such as condoms, at all times to lessen the chances of an unplanned pregnancy even more.