Whilst I dont use Dexcom, I have used the libre and and am now using the Medtronic sensors (they work with my pump) and I also have the contraceptive implant, it has no issues - just need to make sure I know where the implant is when putting the sensor on my left arm so the needle (from the sensor applicator) wont be getting the implant - I tend to give it a few cm's space at least just to be on the safe side (so yes I have a little less space to choose from on my left arm when placing the sensors)
I tend to give my left arm (ie the one with the implant) a couple of weeks rest from the sensors when I get the implant replaced
