How to calculate the due date most accurately? Simple method

Patient's question:

No

Doctor's answer:

Simply add 9 months and 1 week (280 days) to the first day of your last menstrual period. It's best to determine the exact time. True delivery may occur within 2 weeks before or after the due date. If your menstrual cycle is irregular, it needs to be calculated based on a gynecological examination.