Go to My Account, login. Click Code Redemption and check under Code Redemption should say something like this.
CODE REDEMPTION HISTORY
Below is a list of valid Star Wars: The Old Republic codes that have been redeemed under this account.
12.11.2011 Star Wars™: The Old Republic™ Early Game Access: Ready to patch
12.11.2011 Star Wars™: The Old Republic™ Digital Standard Edition Pre-Order