The trip in the "Next Trip" section is either a current trip, if one exists, or it is the next future trip in your My Trips page. That is, it is a current trip if you have one with a flight currently in process or completed within the past hour (completed means it has a status of landed, arrived, cancelled, or past flight). If you have no current trips, then it is the future trip with the flight that has the next earliest scheduled departure time. Note, there may be more than one trip listed in the "Next Trip" section if you have more than one current trip in your my Trips page or if you have more than one future trips with flights that depart at the same time on the same date.