So this is probably a very stupid question but I am buying clothes on forever21.com and would like ouse my $25 American express card that i got from my aunt, however my total order cost $75..so can i use the gift card? and also there is no way that it could somehow charge my aunt the rest of the cost is there, if they dont let me put another credit card on the order, because there is no place on there where i can put my gift card