If you had unprotected sex, you could get pregnant. Take an early-results home pregnancy test with first-morning (concentrated) urine two weeks after the last time you had unprotected sex, or go to the doctor for a blood test possibly 10-11 days after the most recent unprotected sex.
That seems way soon for symptoms, but I guess its possible. If you word it as screwed, then why take the risk??
If you miss your next period, then just take a test.