sorry, i don't know anything about that. the only time i got sent back was when they found a cyst on my ovary. i hope everything is okay. was it a tech or a doctor doing the exam? sometimes a tech will miss something and the doctor will want to get a better picture of it. hopefully it's nothing. good luck!
This is some stuff i read about it:
All ultrasounds performed after 18 to 20 weeks should be level two ultrasounds. This means that gestational age and fetal growth measurements are noted, along with comments about the brain, heart, kidney and cord insertion, amniotic fluid volume, placental position and obvious maternal pelvic organ abnormalities. It generally takes more than an hour to complete.
Level I, which is a more basic exam, would include information about fetal number, fetal presentation, documentation of fetal life, placental location, assessment of amniotic fluid volume, assessment of gestational age, survey of fetal anatomy for gross malformations and an evaluation for maternal pelvic masses.