Ultrasound is inexact. They saw a bright spot on an ultrasound. It might mean many things. It probably means nothing.
Your baby's position at this point is irrelevant. Babies move around a lot. Sorry you're uncomfortable, though. Maybe you can play some music and get her to dance a bit?
If your baby is measuring in the 65th percentile for growth, she's obviously not having her growth affected significantly. This would tend to support the theory that the bright spot on the ultrasound is irrelevant to your baby's health.
When considering tests of any kind, ask these questions:
What will it mean if the test comes back positive?
What will it mean if the test comes back negative?
What is the accuracy of this test?
What is the rate of false positives? False negatives?
What are the risks of the test itself?
What actions, if any, would different test results cause me to choose?
Not all tests tell us anything useful. Feel free to decline tests that will not offer you anything but stress.
As much as possible, take a deep breath and let go of what you heard the doctor say. Talk to your baby. Listen to your intuition. Do you believe there is a problem? If there is no indication of a problem other that a bright spot on a blob on a machine, the machine is probably wrong.