I'm on the ortho evra patch, if a wear a patch during the off week, will i miss my period?

Likely: Continuous use of combination hormonal birth control is likely to result in amenorrhea.

Continuos use: Once you're on the patch for awhile, it's possible to keep the patch on & skip a withdrawal bleed. It's safe to do occasionally but allow a cycle every three months or so. Remember the patch does give higher level of estrogen so make sure you can use it safely (non-smoker, no risks of clots, etc). Most docs have done this for years.