In most cases of first trimester Vanishing Twin Syndrome, there is no physical impact on the surviving twin. A healthy womb experience followed by a normal delivery should be expected. A late pregnancy occurrence of VTS does have some implications for the surviving fetus, just as for the mother.
Depending on how cooked you like your hard boiled eggs, the eggs should be done perfectly in 10-12 minutes. That said, depending on your altitude, the shape of the pan, the size of the eggs, the ratio of water to eggs, it can take a few minutes more.
For perfect hard-cooked eggs, I put the eggs in a saucepan with cold water to cover and some salt. I bring the eggs and water to a rolling boil, remove the pan from the heat, cover and let sit for 16 to 18 minutes for large eggs, slightly less for smaller ones.