We are new to Dex and have only used it for a week, which went very well. My son who's about to turn 15, pretty much managed it on his own. One thing he mentioned to me that I'm hoping you can clear up is that when it asked him to enter bg every 12 hours, even after the initial start up, it asked him to enter 2 bg readings. I thought it only asked for 2 readings at start up, not every time you calibrate. Any insight?