K.L.
It depends on your personal risk factors if this is worth it to you. Most likely it is not. Are you a smoker or overweight? If yes.. You already know what you need to do to decrease your risk. The testing would only scare you straight. With the thyroid ultrasound they are mostly screening for potentially cancerous nodules and noncancerous growths. It won't tell you how your thyroid is functioning like a blood test would. Hypothetically, they find a nodule on your thyroid. They will send you for an official diagnostic (not screening) ultrasound and potentially a biopsy. I see a benefit in doing screening ultrasounds more for elderly most to look for cancers and other conditions in which age plays a factor. My advice, save your money given you are still a relatively young female I assume.