Most people test negative.
Have you seen your results? If not ask for a copy. While you may have had an overall negative result it's possible that you tested positive in a Lyme specific band or two. That would be enough to know without a doubt that you have Lyme.
Why then a negative result? Well the CDC has absurd standards for a test to be considered positive.
The test isn't looking for Lyme. It's looking for the antibodies your body creates to fight against Lyme. Lyme has the ability to hide from your immune system so then of course your body wouldn't create antibodies. If in fact you did not test positive in any bands I'd recommend trying to stimulate an immune response. The most common way is by taking olive leaf extract. You can purchase a bottle of the drops and start with a drop twice a day. Build up from there. Use the drops for 2 weeks before retesting.
To understand the tests lymetwistontherocks.blogspot.com/2011/01/western-blots-what-do-all-of-those-darn.html