Ortho Tri Cyclen Lo

Okay so I've been taking the ortho tri cyclen lo for almost a year now and in a recent discussion with my doctor I told her I was in my past week of pills and she said the white ones were the last week but I've always taking the green because I thought it was the placebo which was to be taken last... Please tell me how you're taking your pills because now I'm worried I'm doing it wrong. (Don't mind the accidental missed pill)