I am recently very new to the OmniPod systems and have only been using it for a week. Yesterday I noticed blood in the cannula window and with one day left to go on my pod I changed it out for a new one. Today I was monitoring my pod closely and noticed blood in the window again! Is this common or a concern? My BG has been fine but I am still worried as I am new to this. Do I need to change my pod every time I see blood in the cannula window?