Does it hurt? I keep reading that it hurts wjen they test you. Why are they testing you if you have had zero symptoms? Can you refuse the test? What happens if you do????

I really don't want to have them test me because I don't feel like having a horrible headache from them shoving shit up my nose. I already have constant migraines and idk if I can handle that pain and then go thru labor.

Anyone been tested before? How bad does it hurt? What exactly do they do?