My husband and I are both heavy pot smokers. Two years ago we purchased large life insurance policies and blood/urine samples were required.
At that time, the samples were NOT tested for cannabis. They tested for tobacco, though. I'm assuming they just check for simple health problems (high colesterol, etc.). I don't think you have anything to worry about. Besides, they wouldn't do drug tests because of the cost. Remember, every test that they do requires time and money. They don't want to do anything that would slow down your paperwork and keep them from making money.