something BIT me..INPUT...???

[Topless In Texas]

Hey ya'll...for all you 'medics' out there! I know there are a few....

I noticed yesterday I had this annoying bite on my leg. No biggie...well, last night it woke me out of a dead sleep(that is NOT an easy task.) It was sore as hell and really tender.
Well throughout the day it is now swelled up about 3/4 to an inch diameter around the bite and like a little red line coming off the top right hand side and the bottom left hand side, sideways. Looks like a hurricane, when they track them on the chart.

Its really tender, and it hurts my bottom half of my leg when I walk...When I poke around on it, its kinda fluidy. Heres some pics...(YUK) dont ya hate when people do this?
The yellow pic actually shows the discoloration of the redness a little better than the clear pic. But its hard to get the right lighting that close up....any idea what it could've been, and do ya'll think its anything I should be concerned about??????????
THANKS FOR THE INPUT! TNT

ignore the fact that i need to shave.