pct with a drug test coming up please HELP???

i was wondering how long clomid hcg & nolvadex can be tested in your system for.. i have a athletic drug test 3 weeks after my cycle ends and i wanted to do pct to get back to normal levels for my race were i'll be tested at... what is the best way to get back to normal and still be able to pass my drug test.. and yes they test for steroids and recreational drugs, but it's only a piss test... i need as much info as possible.. also this is the biggest competition of the year i need to be in the best shape thats why i have to do pct... thanx for any help anyone can give me..