Welcome to our community!! As Mrs Pallas suggested, please do read through our "New to Lyme? Start here!" thread that sits at the top of the forum - it's packed with helpful information!!
The Elisa and Western Blot are not terribly accurate for many reasons, but in nut shell it's because they are only looking for the body's response to the infection - not the bacteria causing it, and they are only testing for reactions to 4 or 5 out of the over 300 possible strains of the bacteria.
Whether you treat with natural protocols or abx (antibiotics) is up to you - members here have healed with each way and many use a combination of the two. I'm someone who healed with using only natural protocols. If your tests come back negative, I would greatly encourage you to continue treatment with your NP.
Your symptoms make me think of Babesia (another tick-borne infection) as well - do you know if you were you tested for that as well? Both Lyme and Babesia can cause pericarditis and those infections will need to be treated in order to resolve the pericarditis.
The fact that you felt better then worse on the Doxy and then worse for a while on the natural things from your NP is a telltale sign of Lyme disease. If you are not detoxing yet, please be sure to read through the "New to Lyme?" thread as detoxing suggestions are in the second post I believe.
Herb only treatment for Lyme & Bart ended Dec. 2011 - no active symptoms
Herb only treatment for Babesia ended Dec. 2012 - no active symptoms
Healed and loving life!www.healingwell.com/community/default.aspx?f=30&m=2977364
Had Lyme, Bart, Babs, RMSF, Ehrlichia, Myco, Anaplasmosis, EBV
Questions? Please email me!!! Click on blue envelop