May not be as far along

Alicia
U/S tech said I was measuring 7 weeks, but after talking with my doctor, was told I could be as far as two weeks behind. So may only be 5 weeks. Very confused, as my LMP was May 1st. I know I ovulated around May 16th, and I first tested positive on May 30th. Anyway, at this point they cannot rule out miscarriage which is very discouraging.