dude..if ur dad is gonna give u a drug test in like 30days id stay off it from now till the drug test is done and dusted...and if u wanna go bk to weed, well thats up to u...its totally up to u dude..but, if i were u i wouldnt touch it untill after the drug test thing...good luck with the drug test and whatever u plan to do...o, and drink plenty of water..heres a link on some ways to pass and get it out of ur system,
http://boards.cannabis.com/showthread.php?t=11015
hope it works out for u, and hope the link is usefull too..
later days!