In the checklist they didn't ask to submit any educational docs. how do they judge that i was on OCWP in the month on July and August 2013?
You said you provided a copy of your transcript and diploma - those usually indicate the end date / graduation date. In any case, it's not a bad idea to submit a written explanation. Sure, the VO should be able to figure it out, but making it easy for them is a good thing : ) Wait until you get your AOR . . .