Hi thanks for your question.
report is absolutely normal.Head fixes duration later part of pregnancy
or sometime during early labour.There is nothing to worry if your gynaecologist plans caeseran section for non engagement of head. There is always a difference in gestational age
by ultrasound and by clinical examination.There is nothing to worry.Ther perfect gestational age is calculated from LMP that is last menstrual period.
Hope thias answers your question.