How much longer do you have to go?
The rest of your life sounds about right.
Getting high for any reason regardless of drug (even pot) usually leads to a life time of poor decisions and regret. If I hadn't smoked pot I probably wouldn't have tried coke. Without coke I probably wouldn't have tried Meth and without that I likely never would have dropped acid. Without all of that there is a good chance I wouldn't have taken those two Vicodin to get high 10 years ago. Those two Vicodin led to taking 15 Vicodin 5 to 6 times per day.
Quit now and live your life to the fullest and never look back. Good luck
For what? We can't give you drug test information/advice.
What I can say is that you made it this far, and so by now you are noticing things being better in a lot of ways.
It is impressive to me whenever anyone stops smoking marijuana on their own just because they want to and not because they have to. Even if it's because they have to, it's a certain substance that is just way to easy to argue reasons WHY to do it.
Just know this, keep going the way you are, you are doing great and you should treat yourself to something nice if you can because you deserve it.
21 days is great! What do you mean when you say how much longer do you have to go? Are you having withdrawl symptoms? I've not really heard of withdrawl from marijuana, just more of a mental "want"?