Dear shandi,

It depends on when you apply your first patch. If you apply your first patch within five days after the start of your period, you are protected immediately.

If you apply your first patch more than five days after the start of your period, use a backup method of birth control — like a latex or female condom — if you have vaginal intercourse during the first week. Patch protection will begin after seven days.

Used correctly, the patch is up to 99.7 percent effective against pregnancy. But remember, the patch offers no protection against sexually transmitted infections — only latex and female condoms reduce the risk of infection as well as pregnancy.

Hope this information helps!

Take care,

teenwire.com^® Editors

This column is for informational purposes only and is not intended to constitute medical advice, diagnosis, or treatment. If you have a medical problem, please call toll-free 1-800-230-PLAN for an appointment with the Planned Parenthood health center nearest you.