Thanks for the query.
Sometimes ultrasound may not detect the fetal pole
in early pregnancy
Usually in transvaginal ultrasound
fetal pole can be seen after 5 completed weeks and in transabdominal scan fetal pole can be seen after completion of 6th week.
But sometimes due to causes like wrong dates, quality of the machine, hormonal
levels etc, fetal pole may not be seen as expected.
If the gestational sac
is regular with normal deciduous layer, there is hope that fetal pole may be seen later.
So you wait for two more weeks as suggested by your doctor and go for repeat scan.
For more details you can ask me directly through the premium forum. Take care.