Hi MAJ04, welcome to the board!
How did you remove the tick? For future reference, save it. It can be tested for disease. PA is endemic for Lyme. You may want to take precautions to prevent getting bitten.
Below is a Lyme symptom list. You can have any combination of symptoms.
Unexplained fevers, sweats, chills, or flushing
Unexplained weight change--loss or gain
Fatigue, tiredness, poor stamina
Unexplained hair loss
Testicular pain/pelvic pain
Unexplained menstrual irregularity
Unexplained milk production: breast pain
Irritable bladder or bladder dysfunction
Sexual dysfunction or loss of libido
Change in bowel function-constipation, diarrhea
Chest pain or rib soreness
Shortness of breath, cough
Heart palpitations, pulse skips, heart block
Any history of a heart murmur or valve prolapse?
Joint pain or swelling
Stiffness of the joints, neck, or back
Muscle pain or cramps
Twitching of the face or other muscles
Neck creeks and cracks, neck stiffness, neck pain
Tingling, numbness, burning or stabbing sensations, shooting pains
Facial paralysis (Bell's Palsy)
Eyes/Vision: double, blurry, increased floaters, light sensitivity
Ears/Hearing: buzzing, ringing, ear pain, sound sensitivity
lncreased motion sickness, vertigo, poor balance
Confusion, difficulty in thinking
Difficulty with concentration, reading
Forgetfulness, poor short term memory
Disorientation: getting lost, going to wrong places
Difficulty with speech or writing
Mood swings, irritability, depression
Disturbed sleep-too much, too little, early awakening
Exaggerated symptoms or worse hangover from alcohol
It is very important to see a knowledgeable doctor. Many doctors do not understand Lyme and treat with outdated protocols. No test is completely reliable, and results can vary by lab. From what I understand, the ELISA or titer is the least reliable test and the one most doctors run first. Is this the test you had done? Most people test negative early in the infection.
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.
Why did you think the Doxy was not working? Doxy is often the first antibiotic prescribed because it can be effective for Lyme and some of the co-infections. Are you aware of the Jarisch-Herxheimer Reaction (herx)? Often, when people who have Lyme take antibiotics their symptoms get worse or they get new ones. When the antibiotics kill the bacteria, toxins are released making them feel worse. It can be scary, but it is a good sign the antibiotics are working. During treatment it is a good idea to document your symptoms daily. One way to do this is to list the main symptoms you have each day with a numerical rating of their severity from 1-10. Over time when you review this, you can see when your herxes occur and how you are responding to the meds.
Two weeks of treatment is not enough. From what I understand, an infection caught within two weeks of the bite needs to be treated with the proper dose antibiotic for a minimum of six weeks. The antibiotics kill the bacteria when they are reproducing which is estimated at four weeks. Six weeks of treatment will cover one growth cycle. If symptoms are still present, further treatment is warranted. A longer infection needs longer treatment. It sounds like your infection is early, which is good. Early infections are the easiest to cure. Getting the proper treatment now may reduce the chance of long-term complications. I cannot stress this enough.
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. He discusses antibiotics and doses starting on page 18. I also recommend the books "Everything You Need To Know about Lyme Disease Second Edition" by Karen Vanderhoof-Forschner and "The Lyme Disease Solution" by Kenneth B. Singleton M.D.