you might wanna call USCIS in this matter, as for me when i called USCIS(twice), i clearly asked them if i was eligible to work, they said "yes" thats why i worked for 2 months without any status yet legal..

but here is the catch what they said to me was "if my h1 is approved, then I will not have any issue and will be considered legal for months that i worked without my status (legal) , but if incase it gets rejected, I would not be considered legal for the last past months (i.e, after my opt expires till i get decision from uscis")..this really frustrated me..I was about to join some university for some status..but thank god..my h1 was approved..

and also you will be stuck with any govt related work..like renewing your state id or driver's license...

but i suggest you to call USCIS to confirm any doubts..

and i heard in some cases they will give you a written proof of what they said..you can ask them to email you..

Good luck