Hi Joe,
I recommend checking the following links for more information on how you may be able to determine whether your Louis Vuitton bag is authentic or not:
1) http://www.thebudgetfashionista.com/archives/the_fake_d...e/how_to_tell_if.php
2) http://www.mypoupette.com/
3) http://reviews.ebay.com/Louis-Vuitton-Is-This-Authentic...idZ10000000000021258
Hope this helps!
-Mike