I have a bite on my lower leg it has a sore in the middle and is red around the bite site. its been there for about a week, but it's spreading and now i'm experiencing body aches ?

Suspect infection: Any cut in the skin can get infected and start spreading into the body. From your description it looks like you have some degree of infection which requires a check by your PCP(Physician/doctor) who can give you antibiotics in case there are signs of infection. Serious infections can cause fever and shock. So do not delay in getting a medical check up. In case you develop fever, it is an emergency