How long should i use back up birth control protection?

Depends: Generally use backup - condoms, abstinence, if you miss 2 or more pills. You should read the package insert because each brand may have a slight variation in their recomendations. If you start the pill on day one of cycle, generally no need for initial back-up. This is considered the ideal method. Many use the sunday start - which is best done in conjunction with back up for first week.