Well, if it is measured by your lmp, I don't have any guesses about why your doctor would want to do an ultrasound that early.
Lets last week she said my beta was 88 which said meant i was 2 weeks and i used the pregnancy calculator and put in my last LMP
How are you getting your "fourth week" count? Is it from your presumed date of conception? If so, the doc would count that as being your sixth week, because the medical count begins at the first day of your last period. In the sixth week (from the first day of the last period) you can see plenty on an ultrasound.
Ok great my doc is trying rule out if i have an ectopic pregnancy i will be fourth weeks on monday and that's the day she ordered an ultrasound but if u cant see anything i wonder y she ordered it
No, I think it would have to be at the fifth week or more. If memory serves, especially early in the 4th week, nothing shows on an ultrasound except possibly a slightly thickened uterine lining, and it apparently takes a good eye for an ultrasonographer to see that.