A four pound weight variation in a single day is completely normal, and six or seven pounds is not unheard of. A stone in a week is kind of a lot but it's not beyond the realms of possibility.
Some things you might want to do are:
-check the accuracy of your scales -measure your weight at a specific time of day (i.e. first thing in the morning, before eating, and after using the bathroom) -always weigh yourself naked -make sure the scales are always on the same surface each time -balance your weight on the scales so an equal amount is on each foot -weigh yourself more than once each time (i.e. step on and off the scales a few times) -keep a log of your weight and everything you eat/drink
Some things you might want to do are:
-check the accuracy of your scales
-measure your weight at a specific time of day (i.e. first thing in the morning, before eating, and after using the bathroom)
-always weigh yourself naked
-make sure the scales are always on the same surface each time
-balance your weight on the scales so an equal amount is on each foot
-weigh yourself more than once each time (i.e. step on and off the scales a few times)
-keep a log of your weight and everything you eat/drink