The phrase "after a class" is correct and usable in written English.
It can be used to indicate a time period following the conclusion of a class or course.
Example: "I usually meet my friends for coffee after a class to discuss the day's lessons."
Alternatives: "following a class" or "post-class".
"It's like I'm clean after a class," Mr. Weisberg said.
After a class on human sexuality, Professor Bailey invited students to stay for an optional discussion of sexual fetishes.
He could so entrance his students that, after a class, they'd be running down the street jumping over parking meters.
The other day, Dominique was in the elevator with Ms. Brown after a class on the cell cycle.
A revolt in August 2010 partly destroyed the center, which is working at reduced capacity after a class action suit was successfully brought against it.
At first I considered the area of statistical genetics, but after a class project in David Brillinger's Time Series course, I became more interested in endocrinology.
His death was reported a day after a class-action sexual abuse and malpractice suit was filed against him in Boston.
But in 1996, after a class-action lawsuit said market-makers had colluded to keep spreads high, spreads on the Nasdaq began to drop.
The city stopped such searches after a class-action suit was filed and in January tentatively agreed to the $50 million settlement approved yesterday.
After a class-action lawsuit was filed last year accusing the company of deceptive marketing, Pinkberry posted ingredients on its Web site.
In its first year of operation, there were six inmate escapes, twenty stabbings (two of them were fatal), and numerous other assaults — figures that came to light only after a class-action lawsuit was filed on behalf of the inmates.
