starting drug tests

The last time I smoked was January 15. During the huge blizzard here, i had my pipe in my pocket, and wet my pant (with snow haha) and threw my pants on the floor and put on new ones and went out. Well my parent did my laundry and found it, so my parents think (know) im toking at my best friends house. i was jus tthinking of quitting until summer (owwie) so i can at least go out and get trashed, so i will tell them ill start paying for a w weekly drug test so theyll let me out. do you think a weekly test will suffice, and when would i be clean from january 15. Also, i heard about some drink you drink withing 2 hours prior to a drug test and it comes up clean?? any feedback welcome.thanks!!!!

**EDIT** I dunno if this matters but im 16, weigh about 225lbs 6'4" and have long hair (hair test?) thanks again!!!