MILFORD - With only three shopping days left until Christmas, stores across southwestern Connecticut are being flooded with last-minute shoppers.At the Target in Milford, Liz Alvarez says customers have been lining up outside before the store opens. In addition to last-minute gifts, she says shoppers are buying snacks for guests and decorations.The store is open until midnight and the rest of the Westfield mall will be open until 11 p.m.