A week ago I strained my hamstring approx 4 days later I noticed some small bruising and later that same night I aggraveted the injury to the hamstring. For the most part, my leg feels much better now (1 week after second occurrence) and the swelling has subsided. I'm gaining the flexibility back but there is a very large bruise which is now covering the back of the knee Is this normal or should I be concerned? There is a bit of discomfort but it's not very painful at all.