Facebook Messenger problem?

Okay every time I log into FB messenger my iPhone app I see I have unread messages on the top… But I don't. Does anybody know what this is?

You are getting messages from spammers, and facebook is deleting their accounts before you can read them… Do you add people you don't know as friends?

Most Likely what's happening is your getting new messages and then Facebook is Deleting them Due to they may be a Spammer trying to Contact you