Worked on expired CPT. Will it affect green card process?

[tinkererg]

I worked on expired CPT for 3 weeks and it was an unintentional mistake. In the year 2012, I had obtained authorized CPT for the fall semester. After the end of that semester, I continued to work without realizing that my CPT has expired. Even my ex-employer did not ask me to provide work authorization for that period. Later when I realized my mistake, I applied for my 2nd OPT and it got approved.

 

Now my present employer is filing for my green card and I'm worried about this mistake. Is there a way to correct this mistake?

 

Will this affect my green card process?