How do i pass a urine test for THC?

Ok well this was wrote on june 11 2011...last summer i smoked tons of weed...im 15...my mom got suspicion and got me with a home drug test (urine)..since then july 2010....she tested me 3 times....in february 11', march11'.and april 11'....well its been 2 months and i passed all of them 3...and i really wanna smoke again but idk if a random home urine drug test might come up? If it does how could i pass it?