This will also be the case if your doctor's office has cancelled and reset your account. If your email address has already been used to create a your initial account, you may encounter an error message stating "username has already been taken."
In these cases, you will need to create create a new, unique username. After updating the username field, you should have the ability to successfully create your account.
If you would prefer to link your records into one account rather than having separate accounts with different usernames and passwords, click here to learn more.