There's no guarantee that they can't pick up traces of marijuana in your blood after more than a month.
And, if you lied on the application for your life insurance about smoking, it will go into your record at the Medical Information Bureau (M.I.B.) about the application being declined. That means every life insurance company will be able to see that information if you ever apply for life insurance again in the future.
Also, there are life insurance carriers that may offer you life insurance coverage without any health exam or testing required. In fact, some "A" rated life insurance companies offer up to $300,000 or more of life insurance without an exam needed.
Make sure you are honest on the application for life insurance so any future claim is not denied when your family needs it most.
Here's how you can learn more about term life insurance drug tests and how you may qualify for no exam life insurance coverage.