I had my citizenship about a month ago and have still not heard from INS

After the interview , the guy told me " congratulation, you are US citizen, we will review your application and you will hear from us".Most of my friends who has been to the interview usually hear from INS three weeks after their interview.
Any advice or suggestion?

Thanks.

Worried immgrant

Wait....

I had mine in May,and I still havent heard from them.I have been told by the INS Customer service that it takes about forty five days.