That third sensor was being a pain. It gave me good numbers for about 14 hours then went ??? and intermittently gave me okay numbers.
At 4:30 this morning, I woke up from a bad dream, checked the Dexcom (it was saying "???" but had been saying something like "steady at 100" as of about 20 minutes prior) got up, went to the bathroom, washed my hands, and climbed back into bad. Only as I was going over the side, the sensor ripped most of the way off of my leg. I turned on the light to take a look, and it appeared to be out; I tore it the rest of the way off, then tried to go back to sleep. I was half glad it was out because it had been hurting so much.
I spent most of the day without a sensor (I survived) and about fifteen minutes ago put in another one. This one is on the side of my left leg (same leg) much further up, about three inches from my butt. It hurt very little going in but a little bit when I stood up. I put this one on so that the needle was pointed straight inwards when I was sitting; the sensor is pointed sideways if I stand up. I hope this position is more secure, and I hope this put it more successfully into fat. I will let you know.