Negative tests....

I had a negative test about a week ago and sat it down with 3-4 minutes. I fell asleep and saw that it had the faintest line with pink color on it(I slept 4 hours btw). I added a drop of water to see if the line would wash away like an evap but it didn't. I took another test today, not fmu, and saw nothing at first then a vvvvfaint line again.... This has happened before and hospital urine test would say Negative and blood work would be neg too. Has anybody ever had multiple tests that were positive but Dr says no? Or has anyone had repeated negative tests but turned out to be pregnant?