Accuracy of expired test kit?

[xtreme]

Just opened an Elos Calcium test kit for the first time since I bought it. Exp date on the box is 04-13 (shows how long it has been since I tested). Tested super low - 150. Is that even possible? Since I have some STN going on with a few SPS I'm wondering if I should put in a somewhat heavy dose of calcium tonight or wait until I can pick up a new test kit tomorrow and go from there?