Yes, scan is just another term for ultrasound.
I'm not sure but I'm due November 21st and I had my period on Valentines Day my doctor told me I got pregnant on the 28th. Everything seems the day before me so more than likely u conceived after ur period. I don't even think u can get pregnant right before because a egg is not released until after.
Like an ultrasound you mean?
If your due date is reliable, by 1st trimester scan, then conception was late February. Did you have a 1st trimester scan to confirm due date?
Says my ovulation date was February 26th , conceived February 27th & implantation date march 7th
I conceived on February 16 and my due date is November 9th