Originally Posted by 2xy
Yes, but they wouldn't change the due date for that.
Another possibility is a technician who got an inaccurate measurement.
I agree, the measurement is only as good as the tech's skill level. And, mistakes do happen. Plus, you have to remember, even the absolute BEST measurement has a margin of error. Before 10 weeks, this margin of error is somewhere around +/- 2-4 days. As you get closer to 20 weeks, the margin of error is more like +/- 5-7 days.
2 weeks is an awfully big discrepancy, though. You just never know how someone's body works, though, nature is often not textbook. And, it is possible to ovulate twice in the same cycle. Usually, I believe, the 2nd O is within 48 hours of the first O. And, not everyone has a 14 day luteal cycle. Everyone is different.
Also, I wonder what usually happens with a loss. Before the loss happens, do you think it is possible for the baby to slow significantly in growth before it's heart stops beating? Just a thought. I'm not sure if there is anything to that at all, but I wonder if it could proceed like that. Don't tell your friend that one, though.