How long does it take to receive H1B approval under PP?

My H1B petition was recently selected in the lottery. It was filed under Masters Cap PP. How long does it take for the approval notice to reach the law firm under PP?

I think it should be around two weeks from the cut off date. around mid May, you can expect to hear progress with your case, either an approval or an RFE

That is correct. As per USCIS update, all PP petitions should be adjudicated by May 31, unless RFE is issued.