Question 1

are conception calculators accurate based off first ultrasound?

Accepted Answer

: Conception determined by "first U/S" are approximate, and do not accurately determine the actual "due date" or ovulation date, as ovulation may be often delayed, and the U/S only measures correlation of fetal dimensions with estimated fetal age, but size and growth rate variations distort the accuracy of either due date or last ovulation.

Question 2

are conception calculators online accurate based off first trimester ultrasound?

Accepted Answer

Early Ultrasounds: The early ultrasounds are always thought to be the most accurate. So, yes. Of course.

Question 3

preg test on 3/20.  lmp 2/7/ ,41 day cycle. last time had intercourse 2/28 ovulated 3/2. how far am i? i know my fetus is 3 1/2 wks, but preg calculator says 6wk? also when is the gestational sac seen on ultrasound based off conception. hcg is 1235

Accepted Answer

Gestational age: most commonly is the date you are seeing in reference to dating of the pregnancy by ultrasound and most other methods. This is based on the first day of the last period.  Timing centers of a 28  day cycle,  13 cycles per year. Ovulation day is usually day 14 of the the 28 day cycle. If ovulation varies, this causes changes in the specific cycle. This two  weeks difference can be confusing.

Question 4

if my first ultrasound said 7weeks and 4 days and my second said 10 weeks and 2 days would be date of conception be accurate? when i put it in a calculator it said 6/19/2021 date of conception?

Accepted Answer

: The expected date of delivery has a leeway or two weeks on either side, so it is not necessary to be so particular about a few days this way or that.

Question 5

conception query could someone i had sex with 2 weeks before my partner be the father of my child? due date, all ultrasounds, conception calculators match up to the date me and my partner had intercourse, give or take 2 days?

Accepted Answer

: The only worthwhile answer &amp; one that will hold up in court proceedings will be a DNA based paternity test. The NIPP is a non-invasive test performed on your blood as early as 8 weeks. They find fetal DNA in your blood &amp; can test it for a variety of things including paternity. Ultrasounds and projected dates can give data, but a surprise at delivery is not worth a wrong call.

Question 6

is conception more accurate based off lmp or 9 week ultrasound?

Accepted Answer

Both is best: The most accurate dating is where the 1st trimester ultrasound is within a week of the LMP dating; that confirms the LMP dating.  If the 9 week ultrasound gives dates greater than 1 week from what's predicted by the LMP then the LMP is not accurate and the ultrasound dating should be used.

Question 7

based on an estimated lmp from an eight week ultrasound to be 10/15/12, what is the very latest possible date conception could have occurred?

Accepted Answer

Need more info: What was the date of your ultrasound. And on that day, what did they estimate the gestational age of the baby to be.

Question 8

could conception occur outside of the +/- 1 week margin of error based on the ultrasound?

Accepted Answer

Yes if: 1) the pregnancy's abnormal and hence not the correct size, 2) the sonographer mismeasured or miscalculated. Otherwise, not really.

Question 9

based on an ultrasound at 9 weeks how can i estimate my ovulation/conception date?

Accepted Answer

Ask your Doc: An ultrasound date of 9 weeks is fairly accurate so your doc can extrapolate backwards and calculate when you most likely ovulated and which days you most likely conceived.  For example, if you were 9 weeks today (11-14-2012) you most likely conceived around 9-26-12 (7 weeks ago).  Remember conception age is always 2 weeks less than the gestational age we calculate.  Take care.

Question 10

i had sex the 10th , 12 , 20th of dec. my first us was jan16th=6 weeks 1 day . i had a 2nd us jan 31st at 8weeks 2 days . my conception for both based off an online calculator says dec 19 . could the 10th be the day that got me pregnant?

Accepted Answer

: Assuming that the normal fertile period is within 6 days of ovulation, and since the ultrasound dates have an error of plus/minus two or three days, the 10th is an outside possibility. The 12th is more likely and the 20th is most likely.

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Doctor answers about:

Conception calculator based on ultrasound

A member asked:

Are conception calculators accurate based off first ultrasound?

A member asked:

Are conception calculators online accurate based off first trimester ultrasound?

A member asked:

Preg test on 3/20. lmp 2/7/ ,41 day cycle. last time had intercourse 2/28 ovulated 3/2. how far am i? i know my fetus is 3 1/2 wks, but preg calculator says 6wk? also when is the gestational sac seen on ultrasound based off conception. hcg is 1235

A member asked:

If my first ultrasound said 7weeks and 4 days and my second said 10 weeks and 2 days would be date of conception be accurate? when i put it in a calculator it said 6/19/2021 date of conception?

A member asked:

Conception query could someone i had sex with 2 weeks before my partner be the father of my child? due date, all ultrasounds, conception calculators match up to the date me and my partner had intercourse, give or take 2 days?

A member asked:

Is conception more accurate based off lmp or 9 week ultrasound?

A member asked:

Based on an estimated lmp from an eight week ultrasound to be 10/15/12, what is the very latest possible date conception could have occurred?

A member asked:

Could conception occur outside of the +/- 1 week margin of error based on the ultrasound?

A member asked:

Based on an ultrasound at 9 weeks how can i estimate my ovulation/conception date?

A member asked:

I had sex the 10th , 12 , 20th of dec. my first us was jan16th=6 weeks 1 day . i had a 2nd us jan 31st at 8weeks 2 days . my conception for both based off an online calculator says dec 19 . could the 10th be the day that got me pregnant?

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