Invisalign Braces - Is it the best ?

Hello!
I am 21-year-old female from Houston. I have heard a lot about Invisalign invisible braces. I don't want people to notice that I have braces so I guess this is the only remedy. I have misaligned teeth in my upper and lower jaw and I feel that I need to get it fixed right away. I have an appointment next week to finally fix these braces from a dental clinic in Houston ( http://www.shorttermbraces.com/services/short-term-braces/ ). I am a little jumpy about it because my pain threshold is pretty low. I don't want to faint or scream my lungs out if it hurts. Can people with Invisalign braces please share your experiences? I would love to hear your stories and prepare myself better.