Abercrombie hoodie- possible counterfeit?

i bought an abercrombie hoodie on ebay. well i always wear a size large in their clothes and they always fit a little loose, sometimes i buy medium. well all my hoodies that are large from a&f are 20 inches across. i got the one from ebay today and it was so tight i barely could zip it. it was so tight on the arms it made my arms hurt. i thought they made a mistake and it was from the kids store. i looked up the measurements for kids and it's 17.5 inches across the chest, which is what this one is. the tag is still there though and it says womens large but i know it's not. is there a chance it could be a counterfeit item?