Urgent H-1B question

I just learned that the 20,000 H-1B cap has been reached yesterday. My H-1B has not been filed yet and my OPT will expire in May . Since the new H-1B will not be effective until Oct 1 ,I cannot work between May - Oct. My boss said I can come back to work in Oct when the H-1B become effetive. My question are :

1. Do I need to change my status during May-Oct if My H-1B petition has been received by USCIS during April and approved sometime in May or June ?

2. Can I work in May and June since the OPT has two month grace period ?

Thanks a lot !