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Ask Dr. Norm S. Your Own Question
Dr. Norm S.
Dr. Norm S., Board Certified OB/GYN
Category: OB GYN
Satisfied Customers: 11230
Experience:  Over 30 years of experience in OB/GYN practice, including teaching students. Fellow of American Board of Obstetrics and Gynecology.
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Wondering if you could help me as I'm getting stressed. I

Customer Question

Wondering if you could help me as I'm getting stressed. I had my first pregnancy dating scan yesterday which said that I am 13 weeks and 3 days. My last period was June 13th which lasted 5 days. My cycle is 28 days. Does this mean that I conceived on June 27th or be possible for July 1st?
Submitted: 1 year ago.
Category: OB GYN
Expert:  Dr. Norm S. replied 1 year ago.

With a regular cycle of 28 days, you likely conceived around June 27.

The scan is consistent with this, although a scan done after 12 weeks is only accurate to 7-8 days. Even a very early scan is only accurate to about 5 days, so usually a scan cannot tell whether pregnancy occurred on June 27 or July 4.

If you had sex with 2 different men on those 2 dates, only a paternity test would be able to tell which is the father. Sorry.