12 week dating scan pregnancy
When I se my ob in a few weeks I'll see what she thinks about officially changing my due date.
From what I've heard,most often lmp is used because most don't know the date of conception but lmp is not as accurate.
There was a really interesting article on the BBC about how some medical professionals think they should do away with the concept of a "due date" due to the 5 week window.
An ultrasound scan sends sound waves through your womb (uterus). The echoes are then turned into an image on a screen that shows your baby’s position and movements.
LMP is only used until the dating scan as it's the best guess until they measure the baby.
The scan measurements are supposed to be accurate to within a couple of days.
My 12 week scan put me like 9 days ahead of my date using lmp!
When I checked against the date of conception it matched up with the scan date.
My lmp is good, because I was keeping track, but I truly don't know when I ovulated, so yeah..moved my edd up a week and lo has been growing consistently within that week's size, so what do I know? The dating scan should be the most reliable, but end of the day you're talking maybe a maximum of 2 weeks discrepancy (which is rare anyway) and as a baby can come over a 5 week period there isn't a need to stress.
I know the sperm can survive a few days so you can conceive later than the day you have sex but not earlier!
My doctor calculates your LMP due date based on the actual amount of days in your cycle.
Both pregnancies we were sure of the date (the first time I was working away loads and this time hubby was working away, so we kinda only had the one opportunity lol! With my daughter the LMP was definitely wrong as my periods were irregular and the scan told us the exact dates we had worked out ourselves.
With this pregnancy however the scan dated conception 4 days BEFORE we dtd.