If you go too long without pooping then it results in impaction which means the poop is starting to harden in your intestines and the harder it gets the more blocked it gets.
Eventually if the poop continues to stay in your body and colon and doesn't come out it can lead to a severe bowel blockage which can result in death.
To die of constipation and not pooping is possible but it would usually take over a month of not pooping or holding in your poop before you actually got to the point of dying from not pooping.
If you haven't pooped within a few weeks then you're likely constipated and need to try some laxatives or try drinking some prune juice or eat some prunes.
If you haven't pooped within 3 weeks you should see your doctor or go to urgent care or the emergency room to get treated just in case you have a bowel blockage.
The doctor may need to manually remove the impacted feces from your anus and use a camera to look up your anus to see what is going on.