I have Lyme and my canine, 7-yr-old female sheltie has lyme, too.
The tests, first off, can be all over the place so even if the test shows you don't have it, listen to your body. You will start having achy joints, tense shoulders, hot flashes/night sweats, tingles in parts of your body, vertigo, all kinds of things. It's known as the masking disease because any symptom you can think of, you'll have. Lyme is a tricky one because it stays dormant for months, even years, hiding out deep inside you and even crossing the blood-brain barrier. The reason it hides so well on the blood test is because it doesn't always hide in your blood. It's cyclical so it hides out sometimes and also the way it gets so deep into you is it turns off you immune system, allowing it to no longer respond to foreign invaders, so you're no longer making antibodies to attack it, you're just letting all the viruses like Shingles, Epstein Barr, all the herpes viruses, etc flare up. So it's important to get a viral panel done, if you have insurance, so you can know if you have viruses before you start doing antibiotics. I am treating it all holistically and I've been on it four months. So far, it's been way more good days than bad so I can't complain.
The good news is it's much easier to treat in canines. Ledum worked fabulous for us. My dog had a limp for 3-4 weeks, I got diagnosed during that time coincidentally and after 3 days on ledum she stopped. She had one flare up about a month later, around the full moon -- watch for cycles -- and the ledum took it away in one day.
I would suggest finding a doctor who is versed in Lyme. If they tell you a couple weeks antibiotics will cure it, and you didn't catch it soon after the bite, you better run.
Email me if you would like to ask me anything as I know a lot about this awful disease. and make note when you have Lyme you have parasites, viruses, all kinds of issues that must all be addressed before one can even attempt to fight the actual spirochetes.