Whether or not you receive an ultrasound during your first trimester of pregnancy depends on a number of factors, including your risk for complications.
At the first trimester scan they confirm that the fetus is alive, they assess the gestational age by measuring the crown-rump length and will look for any major problems.
Ultrasound examination in the first trimester allows accurate assessment of gestational age, and identifies and allows for appropriate care of women with multiple pregnancies.
Methods used to assess gestational age include known date of ovulation, date of the last menstrual period (LMP) and diagnostic ultrasound.
Occasionally the view is not clear and it may be necessary to perform a vaginal scan.
You do not need to have a full bladder, a moderately filled bladder is needed for a proper examination.