My girlfriend and I are expecting our first child. Her last menstrual cycle was september 4th. Had our 1st ultrasound on november 2nd which states that she was 8 weeks and 4 days pregnant. I am just concerned because we had been broke up. She had sex with another man on july 31st. Is there anyway possible the ultrasound could have been off by that much? It would have been off by 4 to 6 weeks???
Don't worry. Conception date would have been around September 16th. The July 31st date has nothing to do with anything. Ultrasounds, especially at 8 weeks 4 days, are quite accurate, maybe off by a day or two. (Later in the pregnancy they are less accurate, because babies grow at different rates. But so early, they can be spot-on to the exact day. They are never off by 4-6 weeks.)
Pregnancy is counted from the first day of the last period. Given an 8w4d count on November 2nd, the expected day of the first day of her last period would be September 2, so everything lines up. She would have conceived a couple of weeks later than the first day of her last period, so, around the 16th. If she had a period in early September, she would have also probably had one in early August, meaning that she had two periods after the sex on July 31st. So what are you worried about?
The ultrasound would have said she was 14 weeks pregnant or more if she got pregnant in July. If the thing that is bothering you is that she had a fling in July, discuss that issue with her separately, but the baby was conceived in mid September. Good luck!
This site complies with the HONcode standard for trustworthy health information.
The Content on this Site is presented in a summary fashion, and is intended to be used for educational and entertainment purposes only. It is not intended to be and should not be interpreted as medical advice or a diagnosis of any health or fitness problem, condition or disease; or a recommendation for a specific test, doctor, care provider, procedure, treatment plan, product, or course of action. Med Help International, Inc. is not a medical or healthcare provider and your use of this Site does not create a doctor / patient relationship. We disclaim all responsibility for the professional qualifications and licensing of, and services provided by, any physician or other health providers posting on or otherwise referred to on this Site and/or any Third Party Site. Never disregard the medical advice of your physician or health professional, or delay in seeking such advice, because of something you read on this Site. We offer this Site AS IS and without any warranties. By using this Site you agree to the following Terms and Conditions. If you think you may have a medical emergency, call your physician or 911 immediately.