When you found some 3 inch long white worm like things in my poop are these worms?

You might have the pinworm infection

Pinworm infection is a large intestine infection caused by a small, white worm called a pinworm.The pinworm is about the length of a staple. It lives for the most part within the rectum of humans. While an infected person is asleep, female pinworms leave the intestines through the anus and deposit eggs on the skin around the anus. This is why most in most cases of Pinworm infection people scratch around the anus.

You should go see a doctor if you think u have pinworm infection, because it will not go on its own. I hope tht i helped :)