Yep absolutely, definitely need to consider this.
Mine is 11 days and still in the "Processing" phase, at least yours has shipped already.
All this being said, the estimate provided by Apple is an estimate and I shouldn't have a reason to believe it will ship earlier than that estimate (though it would definitely be nice if it did ship earlier). Not an expert in these kinds of things but there could be some liability issues if they quote an earlier date and then it ends up arriving later, hence the conservative timelines.