home thc drug testing kits

exactly how reliable are these kits ? i took a lab test for po and then i quickly went to cvs, bought a home test kit and pee'd again for the kit and it came back negative after puffing 4 times on doobie 42 hours before taking test..will i be good for the lab test if two of these tests were negative? thanks freaking out here. im skinny with a high metabolism..i have to call her thursday...its been two weeks come thurs since i took the test and she said call her..my first two were diluted she said. i know this one was not diluted..i barely drank anything and i did what she asked me to do..drink my coffee and one soda pop without ice..finally after all day i did pee yellow for her..thats when i left and bought the other kits and they tested negative..am i freaking out for nothing?