Watch the Chorus After OD online guitar lesson by Jeff McErlain from Guitar Effects Survival Guide
Do me a favor, plug in your chorus pedal after your OD and play for a while. Then reverse that order and play for a while. There is a difference isn't there? Which one do you like better? Do you have an answer? If yes, keep the pedals in that order. If you can't decide, well welcome to the insane world of tone, pedals, and gear!