Hi AVD1000, welcome to the board!
Although only about 50% of people who have Lyme ever get a rash, a bulls-eye rash is a definite sign of Lyme disease. The rash alone merits treatment. Make sure you get photos of your rash, it is important documentation. Place something near it, like a coin or ruler, before photographing to give it size defintion. I could not open the link you posted.
Early infections are the easiest to cure. I cannot stress this enough. No test is completely reliable, and most people test negative early in the infection. It is important to see a knowledgeable doctor. Many doctors do not understand Lyme and follow outdated treatment protocols. From what I understand, an infection caught within two weeks of the bite needs a minimum of six weeks of treatment of the proper dose antibiotic. Most doctors typically undertreat.
Below is a Lyme symptom list. You can have any combination of symptoms.
Besides Lyme, ticks can also transmit several co-infections including Babesiosis, two types of Ehrlichiosis (HME & HGE), Bartonella, and Mycoplasma. Many people who have Lyme are co-infected. It may affect treatment choice and progress. It is important to be tested for these by a Lyme reputable lab such as IgeneX in Palo Alto, CA.
If you need a doctor recommendation, you can email me at firstname.lastname@example.org
It is also important to learn as much as possible. I recommend reading Dr. Joseph Burrascano's 2008 Diagnostic Hints and Treatment Guidelines For Lyme and Other Tick Borne Illnesses at http://www.ilads.org/lyme_disease/B_guidelines_12_17_08.pdf He is one of the top Lyme doctors in the country, and many Lyme doctors follow his protocols. I also recommend the books "The Lyme Disease Solution" by Kenneth B. Singleton M.D. and "Everything You Need To Know about Lyme Disease Second Edition" by Karen Vanderhoof-Forschner.