Hi My Name Is Brian I Got A Bite Of

Hi my name is Brian I got a bite of some kind on my left thigh two weeks ago and the pain and redness is spreading down my leg now to my calf it feals like my mussels in my leg at the area and below are always tight and feels like it keeps spreading on down my leg. My groin area on the same side is sore and little swollen . Don't know if a tick or spider bite but it's not getting any better. Should I see a doctor to get antibiotics ?