I was supposed to start my new pack of orsythia on sunday but instead started it on monday and had protected sex on wednesday. could i be pregnant?

No: Regular daily use of ocps has a <1% failure rate. You were one day late with your dose , and used protection. Next time try not to miss a dose. Good luck.

Yes.: Even perfect use of birth control pills has a 7% risk of pregnancy annually - let alone imperfect use. Take Folic Acid 1-5 mg daily, check urine pregnancy test at home 1-7 days after a late/missed period and best of luck!