While OP's bags would be interlined from BA to AA, AA won't accept the bags from BA the day before departure. Even if BA agrees to hold the bags until the next morning and transfer them, the risk of the bags not making it on such a connection is significantly greater because it depends on an extra set of steps.
Given AA's generous carry-on rules, it should be easy to have the first 3-4 days of clothing, so I suppose if the bags are delayed a day it won't matter so much.