I had my first intervaginal ultrasound today 8/18/2014 and it says am only 5weeks 3days along but according to my lmp wich was 6/15/2014 and a positive pregnancy test on 7/17/2014, I should be 9weeks 1day along. I don't get how that's possible and confused. Any input will be greatly appreciated. Thanks.

It's quite possible that you conceived somewhere in between. Or it is possible that you fell out of the norm when it comes to pregnancy testing and you tested positive earlier than most women do.

Typically early ultrasounds are the most accurate as this is when there are developmental changes in the fetus that happen only during a specific time frame. As you know, when an ultrasound is done, they are not only looking for a pregnancy, but they are also looking for certain organ development. There are changes that happen in stages.