If you are in the vicinity of your high school reunion, or it has passed, you should not be shopping in the junior's department. Nothing in your closet should have odd numbers. Well unless you are a professional athlete, and that's a 50/50 shot. And yes, odd sizes signify junior's sizes.
Our bodies change drastically at the end of, and after, our teen years. Junior clothes don't accommodate adult bodies. The day comes that we must let this go. And that day just happens to be the day after our high school graduations.
The prep starts early though. All the retail heavy hitters, successfully mixing trend, classic fab, and comfort, size for misses and women's. Junior's aren't as glam as you may think. All the cool kids are focused on the evens. It's odd to be odd.