I have heard a lot of things concerning getting pregnant after taking permanent measures initially in preventing that from happening.
Honestly the best close to 100% way to permanently prevent pregnancy is for both partners to go under the knife.
A friend of mine is 25 y o SAHM she has 5 kids rangling in age from 12 to under a year. Her amd her hubby are SUPER fertile people. He now has a vasectomy and she had her tubes tied and burned!
I have in fact heard horror stories of the vas deferens growing back, and women getting pregnant although they have their tubes tied. Its very rare though.
But if it was me both my husband and I need to both get surgically sterilized, just to be SUPER sure.