About two months ago I got bitten by something whilst on ex. Whatever it was bit me three times in an area about the size of a ten pence piece. To start with it looked like three mozzie bites, after a week or so, it looked more like a red circle. This (rough) circle has now grown to around 2-2 1/2 inches in diameter, and the skin in the centre looks slightly bruised. I've been bitten loads of times before, but have never seen any like this, nor has anyone I know. Any ideas on what the Hell it is?