Ultrasound redo? $$

Andrea
So I thought everything was fine after the US. But after my appointment with the OB today she said they didn't end up getting a few of the shots they wanted of the brain so she was sending in a referral for another US. My question is, do I have to pay for this again? My insurance is horrible and we pay for soo much already, i just paid well over $350 for my first US and this one was like $500 so I'm freaking out about having to do it AGAIN.