Please help

[Lollypop4516]

can someone please help me? I had my period in October, no later than the 27th ( I think it was earlier but can't be sure. I slept with my bf that whole month of November but then on the 19th on November I did a very stupid thing I slept with someone else it was very short and he pulled out. I did a test on the 28th  Nov which came up postive straight away and then did a clear blue on the 30th Nov which showed 3 weeks plus. I had a ultrasound on the 21st Jan which said I was 13 week 0days, due date the 29th July. Can I rule out the 19th

[AnnieBrooke]

A person can have more or less concentrated urine and get a different color of line on the same day, or a different hCG count in a lab test on the same day, for that matter.  I stand by what I suggested above but not due to the line on a pregnancy test.

[Lollypop4516]

Hi Annie, sorry to bother you again, can I just ask if I can trust the ultrasound or do I still require a DNA? Thank you

[AnnieBrooke]

Lollypop, I rarely give percents, because percents really don't help.  Even if the number is 99%, an anxious person will always come back with "What if I fall into the 1% remaining?!?!"  and "How can you be sure?" and "Can you GUARANTEE this?!?"  They spend a lot of time trying to  develop scenarios in which it might not be true, and they demand case studies and facts and more case studies and more facts, and frankly, I'm just a volunteer on this site, I don't have databases of comparisons of early ultrasounds and subsequent DNA test results.  I'm here to try to analyze the dates.

When a question is medical you can't say things are 100% sure (except that birth certificates show you were born and death certificates show that you died).  You had sex with two guys relatively close together.  I can see that this is driving you nuts and you want some promises.  And the facts seem to favor pretty strongly that the one you want to be the dad is the dad.  Please let this sink in!  Or, if it is really killing you, get a prenatal DNA test from Ravgen [if you think you will believe what they say].  Otherwise, just tell yourself the baby is almost sure to be from the right guy,  and that things will be all right anyway, and try to relax while you are pregnant.  Then after the baby is born get a DNA test from a certified lab.

I wish you well, there is just no more certainty that I can provide.

[Lollypop4516]

Sorry Annie I didn't explain myself very well. I understand the 7 error rate. It was just you said 85% sure, have you seen cases where the error rate was double the 7day margin? Thank you again

[AnnieBrooke]

Lollypop, I don't know really what you mean by "cases that are wrong in the 11th week."  Your ultrasound has about a week's margin for error due to being in your 11th week, but even a week's margin for error does not quite stretch the possible conception date to as recently as the 19th.

[Lollypop4516]

Thanks annie, Iam just really worried as you have said you would only be 85% sure. Do you find a lot of cases that are wrong in the 11th week. Thank you again

[Lollypop4516]

Thanks annie, Iam just really worried as you have said you would only be 85% sure. Do you fine a lot of cases that are wrong in the 11th week. Thank you again

[Lollypop4516]

Thank you. Am so confused. My midwife said because I am under weight the scan will be clear and at 11 weeks it will be out 6days and 13 weeks maximum 10 days. I take it you have seen cases where this is not the case? X

[AnnieBrooke]

As I said already, I don't think an ultrasound tech would tell you an embryo was two weeks different in size than it was.  With the margin for error, the possible conception date seems to possibly stretch to the 13th but not the 19th.

[AnnieBrooke]

Do you mean when I say "I would be pretty sure," you want me to quantify that with numbers?  I guess when I say "I would be pretty sure," I'm saying around 85% plus or minus 10%.

[Lollypop4516]

Hi Annie, sorry to bother you again, I know you have said you are pretty sure that I can rule out the guy from the 19th. Would you be able to give me a percentage on the chance of the tec dating a 11 week 0 days as a 13 week 0 days baby. I will get a DNA test done but just need to get my head around this before he is here. Thank you

[Lollypop4516]

In short can a 11 week baby be mistaken for an 13 week baby? Thank you again

[AnnieBrooke]

I don't think an ultrasound tech would tell you an embryo was two weeks different in size than it was.  With the margin for error, the possible conception date seems to possibly stretch to the 13th but not the 19th.  It seems that the best idea is to get a DNA test because your dates are still close together.  That would put the whole question to rest forever.  In your shoes I would be pretty sure the guy on the 19th is not the dad.
AnnieBrooke | Jan 20

[Lollypop4516]

Thank you for you time and advice. I know it's not a 100%, Can I just ask would a strong lined pregnancy test which was £1, 9days after the 19th and a 11 days a clear blue at 3 weeks + add any extra weight to your advice? Thank you again

[AnnieBrooke]

I think you can rule out the guy on the 19th of November.  You were probably pregnant by the time you had sex with him.  Your ultrasound has about a week's margin for error because of how late you had it, but even a week's margin for error does not quite stretch the possible conception date to as recently as the 19th.

It wouldn't hurt to get a DNA test when the baby is born, to put the whole question to rest forever, but in your shoes I would be pretty sure the guy on the 19th is not the dad.