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I am currently in the seventh month of pregnancy. I had a history of missed periods but according to the first ultrasound my conception date is 20th feb.As i have read the due date is claculated as 38 weeks from the conception date which turns out to be around 13th of novemeber but my midwife has suggested my due date as 30th of novemeber........I am all confused...someone please help !!!!!!my doctor is currently out of town so can't ask her but I am really unsure and confused.