Ok so i had my dating ultrasound. im a week ahead 8 weeks 2-3 days. they saying definitely over 8 weeks but i thought i was 7 weeks 4 days. we didn't even have to do transvaginal cause she said i'm definitely over 8 weeks. could they be wrong ?

Accuracy may vary: A careful transvaginal (not transabdominal) pelvic sonogram (a "first trimester dating scan") performed by a certified sonographer using a well calibrated machine and proper scannig techniques is usually quite reliable and fairly accurate (plus or minus a few days) in dating your pregnancy. A follow up pregnancy sonogram in a few weeks should help answer your concerns and confirm your dates.