Lyme Disease? Please Help?

About a week ago I had blood work done because I woke up one morning with a slight rash on my body. They were like slight red welts, some bigger than others. It went away within two days. Today I got a call saying I tested positive for Lyme Disease and now they have to do more tests and I have to come back in a week or two. I'm really scared. I don't live near any tick infested area that I know of and I didn't have the classic bulls eye rash from what I could recall. Could this be something else? I would appreciate any advice.