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Ultrasound Dating (Could I be the Father)
The ultrasound was done on March 20th of this year 2017. She says she slept with the other man 11 weeks before(march 20th) and me 5 weeks. I did sleep with her on February 5th I don't know if she remembered or not. Think she's is going when I didn't pull out on the 12th of February but I got her the morning after pill the next morning. The gestational age was based from her last menstrual period 15weeks 1day (which lands in December) that was on the ultrasound i saw. But the size of the baby doesn't add up with 15 weeks. There are two measurements of crown rump length 9.4mm (7weeks) and 6.2mm (6weeks3days) at the bottom of the ultrasound. I was not with her in January, I came back in the picture the first weekend February 5th excatly. She says the doctor said she was 8 weeks and apparently the other guys because maybe the baby is measuring small because of her not getting enough nutrients.
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134578 tn?1483549754
It is interesting that you have the number 15 weeks from her last period, the number 7 weeks evidently from your research of crown-to-rump length, the number 6 weeks 3 days at the bottom of the ultrasound, and that the doc said she was 8 weeks.  But yes, you do have a chance to be the dad, from the sex on February 5 especially.

Why don't you consider getting a prenatal DNA test from Ravgen or the DDC?  They cost a lot, but at least you would not have to sweat this question for the whole pregnancy.  It sounds like the conflicting information you have collected is pretty productive of doubt.
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The gestational age was based from her first day of last menstrual period. 15weeks and a day
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134578 tn?1483549754
I understood that.  If you see my note above you will see that is the first sentence of what I wrote.  Why do you think that is significant?  First days of last periods only matter if the woman is like clockwork every 28 days with a period and it never varies.  From her ultrasound it is clear that is not the case.  
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134578 tn?1483549754
But even ignoring the 15 weeks, you have reported three possible week counts that aren't the same, and you imply they all came from the ultrasound.  

The question is why the doc did not say the same number that the ultrasound evidently said.  It is possible that she remembered what the doctor said incorrectly.

Weeks counts are not that useful compared to counting back from an estimated due date given from the ultrasound data.  Do you know if they gave her an E.D.D. based on the baby's measurements?

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I can send you the ultrasound via email so you can understand what i tried to say
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134578 tn?1483549754
Does it have an E.D.D. written on it?  That is the most important thing.
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Thank you for clarifying that, i was really confused. No unfortunately i dont know her due date.
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The doc told her 8 weeks along.
GA from lmp is 15w1d
Two estimates i think of crl
crl- 6.2mm (6weeks3days)
      9.4mm (7weeks)
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no EDD on the ultrasound
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134578 tn?1483549754
You've got four numbers.  The first day of the last period being 15 weeks prior to the ultrasound is totally insignificant, since women can ovulate any time, and the last period does not lead to the next ovulation in any certain number of weeks.  So, ignore that one.

The second one is that she says the doctor said she was "8 weeks" (presumably at the time she had the ultrasound, but maybe not).  I can't think of any reason a doctor looking at an ultrasound that gives a couple of numbers (7 weeks 0 days and 6 weeks 3 days) would say to the patient that she is at 8 weeks.  The doctor would say either that the patient was at 7 weeks 0 days or 6 weeks 3 days.  However, it is pretty common for women to remember wrongly what the doctor said, or for the story to get garbled in the retelling in some other way, or for the woman to say something the doctor said at a different time and for the person she says it to to misunderstand what she was saying.

This leaves an embryo that is listed on the ultrasound as measuring between 6w3d and 7w0d counted the medical way, which means between 4w3d and 5w0d since conception.  Doctors, nurses, ultrasound machines, medical textbooks, ALL use the method where they add two weeks at the front end to create a "weeks count" of the pregnancy time period.

This is why it is so important to ignore the conflicting weeks counts and to instead simply count back from the estimated due date.  Counting back 266 days from an estimated due date, if it was given based on an early ultrasound, gives a pretty good idea of an estimated conception date, and avoids all of that confusion about adding the two weeks at the front end.  Pregnancy from conception to full term is 266 days. The pregnancy time period, counted the way doctors count it (the "weeks" count), is 280 days from the (supposed or assumed) first day of the last period to full term.  But this particular pregnant woman didn't have her last period two weeks before she got pregnant.  You can tell that because she told the ultrasound tech that her period had been 15 weeks prior; it is typed on her report.  The ultrasound still will measure the actual baby and then compute the weeks of her pregnancy time period using a standard two-week allowance at the front, even if that is not when the woman had her last period.  This is why her 6w3d or 7w0d counts really mean 4w3d or 5w0d from when she conceived.

If she conceived 4 weeks 3 days or 5 weeks before her March 20 ultrasound, it adds up to you and not to the person she had sex with "11 weeks before March 20."  All of that other stuff about 8 weeks and measuring small and stuff is just either wishful thinking or a smokescreen.  No ultrasound tech would mistake a baby at 7 weeks for one at (what would be) 13 weeks (don't forget they add the two weeks at the front end).  Possibly she wants the baby to be from the guy 11 weeks back, but it's not.
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134578 tn?1483549754
If the baby is coming in the first week of November, then it would be from you.
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Avatar universal
Thank you for that awesome explanation, I will update when i get further information.
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have you seen the ultrasound by the way? check your messages just in case
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