Is there a way of knowing if I'm getting a professional stroke screening?

Professional? Do you mean getting evaluated by a general doctor, a neurologist, a stroke neurologist? Or do you mean what tests should be done. If you have not had a stroke, a good generalist, and certainly a neurologist would be able to give you a "professional" evaluation.
Check with YOUR Dr. Some diagnostic companies perform ultrasound tests in the carotid arteries to detect hemodynamic significant obstructions or plaques of cholesterol. Insurances don't pay for this service unless pt. Has a bruit, or signs of stroke or tias. Carotid disease is only one of the possible causes of stroke. There are check lists with risk factors on line you may read.