What can I expect for Invisalign pain?

I have signed up for Invisalign but I'm having sleepless nights worrying about what I have gotten myself into. I have two upper incisors that are somewhat slanted over my front teeth and a few slanted teeth on my lower jaw- and will need a number of attachment.Other than that my teeth are quite nice.Can anyone tell me the pain severity I can expect, is it a throbbing pain?- on a scale of 1 to 10 ??? how would it compare to regular braces. I appreciate all your input.