I wouldn't worry at all. USPS is not the logistical enterprise that FED EX/UPS are, and they are shipping the Magic Bands via Parcel Post (which is not a point by point tracked system like express or priority). You simply don't get the same level of tracking detail with USPS that you are used to with UPS and FED EX (arrival scan and departure scan for all points of the journey).
Mine went from Electronic Info Received straight to 'out for delivery' 4 days later in the DFW area, so in other words, it sat at the info received stage for 4 days while indeed it was in transit.
If I remember correctly, they are shipped from an east coast location(KY or TN if I remember correctly), so your being in CA will add a few days transit as well.