Lost job, I-485 pending

I filed my I-485 2 years ago, just had my second fingerprint done 2 months ago. My current EAD expires next year. Recently lost my job, am looking for a new similar job. May move to another state (will change processing center). For my situation, is it legal to stay in US? How soon should I get a new job? If I inform USCIS that I have changed my job, would they require me to provide information to prove the similarity between two jobs?