Reading the instruction sheet that came with our Novolog vial tonight....."If you use Novolog in an insulin pump, you should change your insertion site every 3 days. The insulin in the reservoir should be changed every 6 days even if you have not used all of the insulin." We are running close with our Animas cartridges until the next shipment arrives.....so now I'm wondering, is it fine to change the site/tubing, etc. every 3 days, but fill the cartridge with 6 days worth and therefore get 6 days use from a cartridge vs. changing the whole system every 3 like we have been? Our CDE said EVERYTHING should be changed every 3 days, but honestly, changing the cartridge every 3 doesn't make sense to me when we have plenty more room for insulin??