after i got popped last year, i look at it like this- on a long enough timeline everyone gets caught. you can take the best precautions, but if they want you they will get you. and nothing hits you harder than that. well, except maybe a cheating wife that takes your kids. depending on your job, when you get busted, it's a pretty life-altering event. i unfortunately had one of those careers where your degree and your certifications are tied together to where if your certifications and licensure is fucked your degree is worthless.
my best advice for those that use cannabis and have jobs that drug test- don't wait, get the fuck out of that profession and do something that doesn't test. because when you get busted, moving your shit out of the house you've owned for years and almost have paid off sucks.
good luck !