I just messed up i took 2 potassium-calcium instead of 1, has anyone ever done this?

I don't think that one will hurt you, but you DO NOT want to make this a habit as potassium can be toxic if overdosed.

I have to take mine only every other day because of other medication I take that hoards potassium in my body.

agree, don't make it a habit. lol. you may have a little racey heart, like caffeine, but should be fine in 24 hrs.