I fell down the stairs almost four months ago and received a deep bone bruise to the shin. The doctor told me it would bruise for a long time, and although it, annoyingly, is still pretty darkly bruised and aches every now and then, I understood that. However, in the past few days I have noticed that my leg now has noticable dent where the bruise is accompanied with some additional pain I have not really felt in the past month. What does this mean?