I usually wear american eagle/aeropostale clothing because abercrombie and fitch isn't anywhere near where i live....I got on the website and found some long sleeve shirts i like but i dont know what size to get because i heard their sizes run different than american eagle or aeropostales. Doesnt anyone know in comparrison what i should get? I wear either medium or larges in american eagle and large at aeropostale. Thanks for the help!! 