Thank you for your query.
If your wife had regular cycles, it is most reliable to go by the LMP.
Also remember that an ultrasound
done in the first trimester is most reliable.
You have to give me the details of the first ultrasound report in order for me to help you most beneficially.
Ultrasounds in the third trimester, 7th month etc are least reliable for calculating the EDD.
Your treating obstetrician is the best judge.
If you have been told to consider 9th March as the EDD, that should be final.
You must go for induction if your doctor advises.