How did you break your fast? With what foods? The wrong foods could easily have brought on discomfort after two weeks of not eating. Otherwise it could just be a healing crisis trying to find another way of manifesting when you broke your fast early.
It shouldn't take long for ketosis to fully reassert itself and your fast will continue on from where it left off. If you did use cooked or processed foods to break it this time please find out more about how to break your fast properly when the time comes again. Raw juicy fruits are the best for this.