So... i had unprotected sex last saturday night. took plan b early monday. he pulled out but i'm extremely nervous... i'm only 17.. ?

Plan B: is ~89% effective in preventing pregnancy if taken within 72 hours of having unprotected sex. This reduces your risk of being pregnant considerably, but there is still a ~10% chance. Hopefully you are not pregnant. You should start a reliable form of birth control as soon as possible, and should always use condoms to protect yourself from STD.

You may be too: young to be engaged in sexual intercourse - if you are having unprotected sex. If you are going to be sexually active and are not ready to bring a child into the world - then be responsible and use protection (every time). Plan B One-Step is up to 89 % effective when taken within 72 hours (3 days) after unprotected sex.