H1B Process Pending - Can I continue to work past Oct1st?

[oceansbud]

Hi,

Thanks in advance for your time.

Introduction:

I have a sitution where, I was in OPTX and have applied for H1B Visa. In the month of Sept 2012, I received RFE for client letter and I responded immediately. After receiving client letter from me, USCIS continued the process. As this was in process, I continued to work past Oct 1st, 2012. I never stopped working and on Oct 25th I finally received H1B approval.

Question:

So my question is, is it illegal to continue work past Oct 1st even when H1B petition is still in process?