What day did i conceive? is the ultrasound tech wrong?

Question

OKAY

so my LMP ended on the 2nd or 3rd of july. i had s*x on the 4th and after s*x there was some pinkish discharge. does this day count as my LMP? because i was not using tampons or anything for 2 days...

i calculated it with this site and it said that

Today is Saturday August 23rd 2008.

You conceived on Thursday July 17th 2008

and your due date is Thursday April 9th 2009.

37 days have passed since the conception,

and you are 229 days before your due date.

You are 7 weeks into your pregnancy,

and you have 33 weeks to go.

You are in the 1st trimester.

I got an ultrasound on the 13th and the tech said i am only 4 weeks, when does that mean that i conceived?

also the ultrasound did not look like a 4 week ultrasound it looked like a 5 week one. we both saw the heart beat and a yolk sack very clearly.

which you cant see in a 4 week ultrasound.

BUT if the tech was right, and i was 4 weeks pregnant on the 13th, what day does that mean i conceived?

p.s.

i had s*x almost every day so thats why im not sure on the day i conceived.

Answer 1

When they date pregnancy from your last menstural period it is from the FIRST day of your last period, not the last day.  

As for the ultrasound dating, the tech probably meant your fetal age was 4 wks, which would have made your gestational age 6wks, so if you were 6 wks on the 13th, then on the 23rd-today-you would be 7wks 3 days.

Ultrasound is MUCH more accurate than LMP for pregnancy dating. So, if I were you, I would assume conception occurred +/- 3 days of July 23rd.

Answer 2

Most woman ovulate about 14 days after their period. That's probably about when you conceived.  

Answer 3

if the tech was right you conceived on the 30th

the first day of pregnancy begins at week 2

that being said it is more accurate to count back 14 days from the next day your period would have started and use that as the day you conceived