It is important that you follow up. For your application to be sent to the Admissions Committee it has be listed as "ready for review". If it is listed as "submitted", it means that you sent your application but it is not necessarily complete. There might be some documents or test scores missing. You application might be stuck with the administrator, and if you do not get it complete on time, it might not even be reviewed by the committee at all.
Make sure to get a confirmation that your application is "ready for review"
