Stay on top of incoming information by viewing all unread and read notifications. Your Notification Center will only show Notifications that have been sent to you, rather than every notification in the entire site.
To see your Notifications:
Select Notifications.
Select View All Notifications.
Use the filter to view either Unread or All (unread and read) notifications.
Your unread messages will also show a count on the Inbox tab of your left side, vertical menu bar. Unread messages are shown with a bold subject line, bold name(s), and a pink dot next to the profile picture of the sender.