sounds like your bf baby to me (:
I had a vaginal ultrasound at 8 weeks they cant see your baby when it is really young with a belly ultrasound.
I looked at google pictures of babies mines age and compare sizes. when I googled 8w ultrasound I got a pretty accurate image they looked about the same size as my baby. so I got confident about that. im pretty sure at 11 weeks and under all babies grow the same.
I don't think even the best ultrasounds can see much before the 5th week.
my due date is dec 3 2014. when my baby was 6 weeks I could see a clear yolk sac with a baby beside it. but that was it. it looked like a blob. im not sure what a baby looks like at 3 weeks pregnant honestly.