Hi. I Woke Up Last Wednesday Morning With A Rash

Hi. I woke up last Wednesday morning with a rash on my upper thigh. I didn't think much of it. Figured it was a spider bite and would go away in a couple days. Well, here it is Sunday and "the bite" had not gotten any better. There's a rash about the size of a half dollar and a fluid slowly oozes out. Hence leaving a wet spot on my underwear and my shorts. It doesn't seem to get any worse but not getting any better either. I scrub it a couple times a day and put alcohol on it after. It doesn't seem to help.