All depends how long your period regularly is. Its different dates if it's 28 days or 36 days...
Your best idea is your first sonogram. According to the calculators I was due May 10 but the date due to the baby's size and milestones is more like the 19th. which makes me sad. I want him to come sooner.
If your last period started February 21st that makes you 9w2d today with an estimated due date of November 28th.
My last period began Feb 21th as well, and I am 9 w 3 d today
With my first pregnancy my doc gave me a edd but said it's an estimate the baby will come when it wants to lol
I agree that it depends on how long your usual cycle is, that would determine when you ovulated and hence got pregnant. My first ultrasound measured what the calculators said. But I was using NFP and tracking my cycles closely so I knew my ovulation date