I've not had Lyme disease but know of people who have had it.
Very unpleasant and it's life-changing effects need to be taken seriously.
Don't piss about asking questions on here, don't delay seeing a doctor and as has been said insist on a blood test.
If it is Lyme disease the sooner it is treated the better, it can become much worse than just a rash on your leg.
Sorry if I'm being all doom and gloom but it can be that bad and seriously affect your health and future well-being.
http://www.nhs.uk/conditions/Lyme-disea ... ction.aspx
Read the comments and you will see that even among doctors there is not enough knowledge of Lyme disease. Many people experience the bad diagnosis situation, told that it can't be Lyme disease but then suffer for months with the symptoms, 2 of the people I know of were like that. Untreated it only gets worse and will severely affect you.