Your invoices will be auto-generated by the system and sent to your email 1 week and 3 days before due date. After that it will again send overdue reminder 1 week and 1 month post-due date. Please disregard the emails if you have paid or have made arrangement for payment.
You can access your invoices in the Client Center. Go to Billing > My Invoices and they will be there. You can view the invoices online, or in PDF format and print them out for reference.