After H1B approval , should I wait for 2 weeks notice, Pijing pl

Gurus,

I am working for company A, they submitted my H1B transfer from company C to A and got receipt in 04/2010, the case is still pending (under initinial review) .

Now I got a offer from company B, they did H1B transfer from company A to company B by using premium processing and got RFE, this lawyer replied RFE by providing my payroll from company A,C , W2 and previous h1b Rceipt. The case got approved.

Company B is pushing to leave right away while I am asking to give company A 2 weeks notice. So is there any risk to continue with A for another 2 weeks ?

Thanks in advance!