Hi doc

I had my ultrasound done on July 3, which say 8 week 1 day old. My first date of my last menstrual period is April 24, 2015.
I am at a 35 day cycle.
Also on May 13 - 16, I have blood spotting.


1) for my ultrasound on jul 3 2015, it dated 8w1d. it is the gestational age. But it is actually measured by the fetus size. So is it really a gestational age? Please confirm.

2) per my blood test did on June 9, I was told that I was at my 4th week. So my doc was very confirmed that I must have conceived in the week of May 10-16. Is that true?

3) I understand that the Calculation of expected due date is done by Naegle's formula, and it is applied assuming that the lady has a normal28 day cycle, then add 9 months and 7 days to last menstrual period to calculate the due date.
I have prolonged menstrual cycles (35 day) then the due date is calculated by the first trimester ultrasound. Whatever the fetal age comes, assume it to be gestation age and retrospective calculate the last menstrual period according to it, and then apply Naegle' s formula to calculate the the due date. So in this case, if I am 8w1d (may 7 2015) per ultrasound, though it is measured by fetal age, we still assume it to be gestational age and treat it as LMP and calculate with Naegle's formula? Is my understanding correct? So would I have a due date of January 31,2016 base on LMP on April 24, 2015 or due date of Feb 11, 2016 based on May 7, 2016.

4) with the above info, what would be by due date and conception date?


Many thanks