Ultrasound Dating

Jane Foley's picture


Dear Ms. Ultrasound,
Hi I need some help on answering a few questions from a professional.

I was on the pill and during my seven day break had sex with an ex partner I got a period 3 days later. Sex took place on the 09th August and had a period on the 12th August.

After my period I didn't continue with the pill as I have irregular periods I only took for a month to get them started as they hadn't come for a few months.

I had my very first ultrasound on the 7th Oct and the lady said I was 6 weeks 2 days, and would have conceived about 4 weeks ago.

I had a second ultrasound on the 17th Nov 08 by a different lady who I told I should be 12w 1day and she said the baby was slightly bigger measuring 13 weeks, but she would keep my due date of 31/05/ the same.

Could the ultrasounds be out 3 to 4 weeks and I could have conceived on the 09th Aug 08?

I know a paternity test is the only way I could be extra sure. I have had a Non-invasive Prenatal Paternity test done from genetestlabs.com. Which used my blood to take fetal cells from and compare with my current partners dna and it showed a match with all markers but the results are 99% accurate.

What is your opinion on this?

Many Thanks for your time



Hi Kerry
My professional opinion is that your current partner has a high probability of being the father of this child. Since you had that very early ultrasound, I feel comfortable saying that you have no worries about the Aug 9th possibility.

You also had a period after that conception possibility, the paternity test came out in your favor and the ultrasound results are very, very strong in your favor. I now give you permission to let that paternity possibility go.

Once your child develops and grows you will see your partner in the child over and over again. So relax! An early ultrasound is NEVER that far off Smile

With regards,
-- Jane RDMS