No. You cannot work without your H-1B petition having been approved. You could have only done that had you now still been in H-1B status and were changing employers, which is not the case in your situation.
If your H-1B petition gets ultimately denied, then yes, you will fall back under H-4 status, as long as it will stil be valid on its own merits (i.e. your spouse will still be in valid H-1B status and your H-4 is still valid.)
Behar Intl. Counsel 619.234.5962 Kindly be advised that the answer above is only general in nature cannot be construed as legal advice, given that not enough facts are known. It is your responsibility to retain a lawyer to analyze the facts specific to your particular situation in order to give you specific advice. Specific answers will require cognizance of all pertinent facts about your case. Any answers offered on Avvo are of a general nature only, and are not meant to create an attorney-client relationship.
You are right. You can't work until USCIS approves your H1B.
This answer is of a general nature and should not be relied upon as final, nor is it intended as legal advice. Consult with a qualified attorney before making any legal decisions. Gen Kimura, (832) 247-6932.
Don't get legal advice from your husband, unless he is licensed as an attorney in the US.
Talk to your company's immigration lawyer ... I am sure that he/she will say that the receipt alone is not sufficient for you to start working.
PROFESSOR OF IMMIGRATION LAW for over 10 years -- This blog posting is offered for informational purposes only. It does not constitute an attorney-client relationship.