according to the ultrasound
result and pregnancy
test results the possibilities are,
- you didn't mention whether your periods are regular or not,
in case of irregular periods
the ovulation might have delayed and that may be responsible for your lesser gestational age
by ultrasound and test compared with date.
-in case of regular periods may be what the doctor told was right.
now if there is no active bleeding, you wait for one more week then repeat the pregnancy test and ultrasound.