reference checks are typically more about when you worked at the company, your position, your salary, etc. its not really about how good an employee you were or details about what you actually did.

companies won't really disclose such information due to potential liability issues.

so, if you didn't lie about anything on your application, there's nothing to worry about. its one thing to exaggerate what you did on the job, its another to lie completely about stuff like your grades, whether you really worked at a company, etc.