My son wears the Medtronic MiniMed 640g pump, and we usually use the SureT catheter. Sometimes we see some blood in the tubing close to the insertion site. We were told by a nurse from the hospital to change the catheter every time this happens. Today I see a tiny bit if blood, but it's been such a good "D" day, this catheter seems to be working so well I'm reluctant to change it just yet. How do you approach this issue?