The test results that came back negative may well have been the not-very-accurate standard tests that nonLyme docs tend to use, a two-step test
regimen of ELISA
and Western blot. If the first one comes back positive, they do the 2d one; if the first one comes back negative, they send you home with a pat on the back.
So YES, a definite YES, that you should question it. Not only could you have Lyme, but also other separate infections that the nasty Lyme ticks often carry as well.