Will my braces hurt that bad?

I have to go and get braces this morning, and I had upper braces in October of last year for about three months, and then they took them off so that they could give me a bionator appliance to push my lower jaw forward. I had to wear that for seven months in all, so today I sort of complete the process by getting braces. My orthodontist said that my teeth are pretty straight already, so will they hurt that much since they are not that crooked? I remember getting my upper set in October, and they didn't hurt that much.