QuestionIm wondering if you can put some ease in my mind. I had a transvaginal ultrasound done on june 11 dating me at 6 wks 3 days...they told me my conception date is may 11...how many days off can this ultrasound be if it had put my lmp on april. 27 and i know for a fact that wasnt my lmp because even though i dont remember exactly when i started i know fore sure it had ended april 26. And now it brings me to my other question of who would be the father if i had sex with person A april28-29 doing the pull out method but have been with only person B throughout all of may. Im scared it might be person As becauase i read that sperm can last 5-7 days and early ultrasounds can be off by one week
AnswerHello Kris,
You've asked several questions, so I'll answer them individually. First, an early transvaginal ultrasound has a standard error of measure of +/- 3 days, but is typically accurate to within +/- 1 day. It cannot be off by a week.
Second, the reason that your LMP isn't matching up is because you didn't ovulate on day 14 of your cycle. Your May 11th conception date would be accurate and this would mean that you simply ovulated later in your cycle than day 14.
Third, there's no way that man A is the father. Yes, sperm can live up to 5 days in fertile cervical mucous, but since your conception date of May 11th is more than 5 days after your dates of intercourse with man A, it's just not possible.
Man B is the father.
Best,
Catherine
