I know exactly when my LMP was and exactly when I ovulated....

Megan
LMP - 10/8
Ovulated - 10/23
That should put me at 6 weeks EDD 7/14. But the ultrasound tech told me I'm measuring 5w 2d, that's like a whole week!!! I talked to the nurse and she wasn't concerned but I'm uneasy about it! Anyone with the similar circumstance???