Let me see if i got your problem. You forgot the email address that you used to register for the exam. If that the case, there is no problem since I would assume you know how to access it. Afterall, it is your own email address
Having said that, nobody can stop you from registering and taking the exam again. You can take the exam as many times possible. IBM won't charge for that.
If this isn't your problem, let me know.
