Wirelessly posted (BlackBerry8830/4.2.2 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/105)

You could check bags in EWR even if the stopover was 4 hours, not 4 days.

Actually were you a non-elite (or if you are; mobile site doesn't display profile info ) you would be subject to bag fees on the Midwest->EWR segment because it is not continuing immediately international and therefore is treated as a domestic segment.

But you can add more bags at intermediate stops if you want, as long as you are within the rules for number of bags or pay the overage.