The burning is the nerves regenerating. ..unless you notice the skin red and inflamed. ..if that happens aee a Dr. If the burning gets unbearable see a Dr as there are medications that help. I used to feel the water moving around and I think it was just that ...moving in the expanders. My 1st fill was 6 Months later as I had 300mls in at time of surgery. It was 6 weeks until the discomfort and pain settled for me. My 1st and last expansion didn't hurt ...just felt tight. But I had good strong pain relief ready if it hadn't been. Things will improve. Take care. Kath x