When i had went to get my ultrasound done on april 10th, 2012. i was 7 weeks and 3 days. when did i conceive?

5 weeks and 3 days: Usually conception happens in the mid cycle which is in a 28 day cycle would be roughly 14 days after the beginning of the last period. Ultrasound measured dates are also based on the last menstrual period, so if you were measured 7 weeks 3 days, this means you conceived roughly 5 weeks 3 days ago.

On or around March 2: A 40 week pregnancy is based on the first day of the pregnancy being the first day of your last period. Ovulation usually is on day 14 of a 28 day cycle. So you are officially 2 weeks pregnant at the time of conception. Confusing. Sonos use the same scale. So on the scan you would be 2 weeks on march 2. Sono could be several days off but less than an week off either way so you have a range +/-.