Twins are the result of one of two things happenings.

sometimes women release more than one egg during a cycle. If both get fertilized, the woman would have what they all fraternal (non-identical) twins.

sometimes one egg is fertilized and then cleaves, or splits into two separate embryos which would result in (identical) … Read more
answered question
Normally during a tubal ligation, they cut the tubes, they tie them and they cauterize (burn) the ends. While anything is possible, it is highly unlikely they would not only have the burned part slough off but that the two ends would grow together and reconnect on their own.

If you wanted to there … Read more