Infection?

Looks like I've picked up an infection although it looks more like a really nasty bruise. Came on early last week and felt like I had flu initially, then a real pain in my leg which meant I couldn't even stand comfortably, let alone walk. I started antibiotics and increased my painkillers and it does feel better than it did, but the colour is really deepening and it really does look badly bruised. I'm waiting for an opportunity to get a second opinion, but after such an encouraging couple of weeks walking this is a real frustration. Just goes to show that it doesn't pay to get carried away with success any more than you should get really down about a bit of a setback.