After passing the exam, you should receive an e-Mail from Microsoft with instructions for registering at the MCP site. Once you follow the instructions and get registered, you can login with your Live-Id at any time and view your Transcript, which lists
all of the exams that you have passed.
It takes a few days to receive this message. If you don't receive it, call the regional service center and explain your trouble. They should be able to fix it.