Thanks for the query.
According to your last menstrual period the gestational age
should be around 9 weeks by Oct 23rd.
Generally by that time fetal pole
along with cardiac activity can also visualized in ultrasound
So the possibilities are wrong dates or blighted ovum
You better wait for one more week as suggested by your doctor and undergo repeat ultrasound which can found out the actual cause of growth lag of the fetus.