Hi! Yes, CAS ultrasound (Carotid Artery Stenosis) is usually done on the neck area, hindi sa pelvis, it checks the blood vessels in your carotid arteries para makita kung may blockage or narrowing, especially important if may stroke risk or symptoms ka like dizziness. Pelvic ultrasounds are different, those check your reproductive organs, bladder, and organs sa lower abdomen. If your doctor recommended CAS ultrasound, it's because ng concerns sa circulation, not pregnancy-related stuff. Best to clarify with your OB or doctor kung anong exactly ang reason nila for ordering it so you know what to expect!