H-1 B Ext, Approved I140 from previous employer, PERM not started by current employer

[[email protected]]

Hi Friends.

I have a few questions.

My current situation.

Im in my 7th year of H1B visa. I completed my 6 years of H1-B with employer A and also have my I140 approved with Employer A. I filed for my H1b Extention with the approved I140 and I got my H1b extention for another 3 years.

After this I moved to employer B and have been working with employer B for over 1 year now and my PERM process has not yet started. My current I797 form or H1B extension with employer B expires in March 2018.

So by March 2018 should I have my I140 approved to be able to extend my H1B for another 3 years? What If my labor is still under process by March 2018?

Thanks for your help.