A level only one tenth of a point greater than a statistically (and lab determined) normal upper value is not very alarming, given that these values are usually given for normal body functioning and not fasting state. Calcium being the case, the body certainly moves it around during a fast - from places where it doesn't belong anymore, like old inflammation sites where it used to neutralize acidity, from bone spurs and other tissue calcifications back to the bones. I would not be too afraid of such minute change in your calcium levels; or maybe would - if your calcium was really low before starting the fast.
I went back in the thread to check your urine pH. 5.5 is still in the normal range. It can go down 4.5-4.6 and still be considered normal. Same thing, these are values for normal conditions. Although, I agree with your cautious approach, since as you mentioned, no medical supervision is available to check on your fasting process. And I do agree that any disciple of natural hygiene knows better than having chronically acidic urine pH under normal conditions. In fact if the body does not overwork itself onto its way up to a slightly alkaline pH, the urine should be neutral or slightly alkaline.
Please, do not forget magnesium and sun exposure for the calcium to get where it belongs - the bones, now that you are ending your fast.