So tomorrow will be three weeks with my Dexcom and I really WANT to love this thing. The problem is its so far off sometimes and feel like I'm just wasting time and money with it. My first sensor (abdomen) lasted 13 days, which I thought was great. It had moments of accurancy but for the most part it seemed to be way off. My second sensor (also abdomen) was great! I thought FINALLY, then after 4…