How long do I need to be taking birth control before I am protected from pregnancy?

You'll be safe after taking the pill for seven days, providing you take your first pill on the first day of your period. This will prevent the next ovulation cycle from taking place.

EDIT: Angela before you start rating people down, do your research. The Ortho Tri-Cyclen site below clearly states seven days.

http://www.thepill.com/thepill/faq.html

Take a look at point , at the top of the page, in purple writing.

You should always wait a month after starting birth control or a new birth control to give your body time to adjust and for it to take affect. During the first month there is still a possibility of pregnancy. And even after that month you should still use condoms every time you have sex because the pill isn't 100% effective.