Well, first of all calm down because if you get this stressed out, it will cause your next period to delay which will make you think you're pregnant when you aren't. You definately are at risk for getting pregnant because it takes one month of pills for the birth control to be in full effect. I would suggest staying calm. The rule of thumb is not to freak out until you've actually missed a period. So, just wait and if your period comes on time, then you'll know.
Just take this and use it as a tool for learning. Even on birth control, you'll want to use protection because even birth control by itself is not 100% effective. Also, it doesn't protect you from std's. It is always wise to protect yourself if you know you're not ready for a baby. You may have gotten lucky this time, so don't worry about it until you miss a period. If you miss a period, go to your local planned parenthood for their tests and you'll know. You'll be fine.. Make sure and keep us updated!!!