H1 B Reciept not recieved For 2012

My Employer said they have filed my visa on May 9 2012.

But still i didnot recieve any Receipt Number

If it is delayed, Once i get receipt Number can i change it to Premium Processing.

Thanks.

According to the official notification it can take upto 60 days to receive your receipt if filed under regular processing. Yes, once you receive your receipt number your employer can update your case to premium processing at any time you wish to do so.