The Enfield-born stopper has made just one Third Division substitute appearance this season, but started Town's 3-1 victory on Tuesday.
Stephens impressed the Ryman Premier side during a pre-season match, and manager Justin Edinburgh quickly brought him in on a four-week spell.
"Kevin played well against Billericay in pre-season and this will do him good," said O's manager Paul Brush (pictured).
"It's a chance for him to play 90 minutes on a regular basis at a senior level and it will be a valuable experience for him."
Meanwhile, trialist Adrian Deane played the full match in the club's 2-0 reserve defeat to Fulham at Motspur Park on Wednesday.
