The COS adviser will review your application and supporting documents before it is mailed to the Immigration Office for processing. Application processing times vary and may be rather long; for current processing times see https://egov.uscis.gov/cris/jsps/index.jsp . USCIS will issue a Receipt Notice acknowledging that your application has been received. Using your receipt number you will be able to check the status of your application on line at http://egov.uscis.gov/casestatus/landing.do . We will notify you by e-mail when the approval notice (Form I-797) is received by our office.
You will not receive a new entry visa stamp with your change of status approval. If you travel outside of the U.S. after your change of status approval, you will have to apply for a new visa stamp while abroad to be able to return to the U.S. in your new non-immigrant status.