Weird bruising on leg?

okay so I know a bruise wouldn't normally be something to be worried about, but I'm a huge hypochondriac 😂 I haven't been injured recently and there's nothing I can think about that would've caused this. before it actually appeared physically I had some itching and soreness in the area, but that was about it. it's actually a pretty large bruise and I've had it for about a week now. should I be concerned?