OLIVIA-
My "friend" is very light when she comes into town and I've never had cramps. Oddly, she comes and goes and I often don't even remember just "when" she was here. SO, I had a heck of a time thinking back as to when the last date of my friends arrival was.
I know that the ultrasound technician said that in the first trimester is the most accurate on age, and even then could be off in either direction by as much as up to two weeks.
I found out I was pregnant when I was 8 weeks and 6 days along roughly and that puts me being due at the end of March of next year. So, we'll see just how accurate their measurements are readings are! (I'm about 23 weeks along now...and I no longer have a belly button!!

)
If I develop and outtie, I am SO putting a bandaid over it.