I know im being superparanoid but still..

Heres my story, im 6'0 about 190, male, somewhat semi-active. I know my bodyfat percentage is about 17%. I used to be somewhat a heavy smoker, in early Sept I smoked about half a blunt a night of some strong stuff. I stopped cold about mid Sept and havent smoked at all since. In late Oct I was told there would be drug testing done in a month from that time(so late Nov). So I figured by the time the testing would come I would be clear(2 months). Anyhow just to be safe I bought a 10-pack of THC test strips on ebay for about 15 bucks. I tested about 2 weeks ago and first sample was positve. I was shitting bricks but then realizes I submerged the strip too deep into the urine. I tested myself again a few hours later and came up negative. I have since tested myself maybe 5 times since then and all were negative. I just wanted to find out how accurate these tests are...I guess im just paranoid because that first sample came up positive.

I wanted to know if anyone here has passed these self tests but came up dirty in the lab? I think I might just buy another self test kit at Walgreens or something just to reassure myself. I was also thinking of looking for a lab somewhere in my city and taking one there. If i come up positive at the lab id have to start looking into some kind of dilution. im jsut really afraid that maybe these lab tests test more clearly or have lower cutoff levels then these home tests. ive been doing alot of research on this and have found a few people who still test dirty after 60 days.

thanks