I wore the second sensor for thirteen and a half days. It was nowhere near as good as the first sensor. The first two days were inaccurate. Five days of pretty good function followed. So I restarted the sensor. And oy! After that it seemed like there was ??? as often as there were numbers, although what numbers there were, were accurate. I wore it in my abdomen and wonder if this made the difference.
Last night I pulled the sensor (while it was ???ing), took a long bath, and then, with my mother's help, inserted the third sensor. It is in my left thigh. We debated whether to put it going up and down or sideways. I think maybe we should have done sideways but we put it so that it runs lengthwise on my leg. It hurt going in, and the muscle area there is tender. I am kinda limping. In the twelve hours or so since it started reading numbers, there have been a lot of ??? areas, although when I calibrated it this morning, it was only 2 mg/dl off of what the meter said.
I will post a chart in another week when I next upload my Dexcom data, and it will be very obvious how much better the first sensor performed. In 16 days of the first sensor, I got a minimum of 246 readings per day. Now? No way!

My blood sugar meter average is up but I'm really hoping that's because of what time of day I've been calibrating, and when I'm choosing to double check the Dexcom (ie, when I need a largish correction).