No, lyme doesn't affect pregnancy test results. But, if you are on Abx and also using pills to prevent pregnancy, they may become less effective and you may become pregnant.
A negative pregnancy test may not be 100% accurate, but it is probably almost impossible (unless someone deliberately altered the test tool) to get a + pregnancy test without being pregnant.
Post Edited (Simela1) : 3/5/2015 1:14:26 AM (GMT-7)