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Avatar universal

Conception date confusion

The due date I've been given is Thursday 17th of December.

I've calculated this and used different conception calculators and the most likely date of conception/ovulation I've come up with is Thursday 26th of March.

I'm just wondering could this mean I conceived BEFORE or AFTER this date. By after I only mean a day after.

I had sex on the 24th (a Tuesday) and then on the 27th (a Friday).

This past Thursday I was exactly 20 weeks according to measurements of the baby. I am now 20 weeks and 2days.
5 Responses
134578 tn?1546634665
COMMUNITY LEADER
Yes, you could have conceived a day before or a day after.  How early in the pregnancy were you given the due date?  Was it from an ultrasound or a little wheel or a calendar?
Avatar universal
My due date was given from the ultrasound.
134578 tn?1546634665
COMMUNITY LEADER
And, please answer because this matters, how many weeks along in the pregnancy did you get the due date, and was that when they gave you the due date?  
Avatar universal
It was given at my 12 week scan but I found out I was actually 13 weeks so a week ahead.

I am now measuring exactly 20 weeks and 3 days.
134578 tn?1546634665
COMMUNITY LEADER
OK, to respond to your question "I'm just wondering could this mean I conceived BEFORE or AFTER this date. By after I only mean a day after.  I had sex on the 24th and then on the 27th" --

If you were given a due date from an ultrasound in your 12th week, yes, absolutely you could have conceived before or after the 26th.  By the 12th week, when using an ultrasound to try to estimate a conception date, the usual margin for error given by the doctor is +/- 7 days either way.  That means sex any time from the 19th of March through the 2nd of April could have produced the child.  As your pregnancy progresses, your ultrasounds will get less and less accurate for dating the pregnancy, because babies grow at different rates.  If you had had an ultrasound at 5 weeks 6 days, I'd tell you that possibly there might be a day or two margin for error, but by now, you probably have almost a two-week margin for error.  So, nothing you can tell from ultrasounds will pinpoint exactly how far along you are or when the pregnancy began with enough precision to be able to decide between sex on the 24th and sex on the 27th.  

Only a DNA test will answer the question, I'm afraid.
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