Did your doctor tell you to wait a certain period of time while starting this birth control before having sex? If so, did you follow his directions? If you did, you shouldn't be pregnant. A home pregnancy test will answer your question first thing tomorrow morning. If you don't get your period within the next day or two, I would definitely call your doctors office and ask to speak with his nurse. She will be able to advise you on what to do.
Excessive worry/stress can often delay or even prevent a period. Try some hot baths and some relaxing and fun times with friends. Just be sure to take some Tampons with you!
Let us know how you're doing, OK?
Peace
Greenlydia