My father was in California on his final leave prior to embarkation on a troop ship for the invasion of the Japanese home islands. My mother was working out there so she could be with him until he shipped out.
When they heard about the bomb being dropped on Hiroshima, they decided that he would probably come home alive. I was conceived as a result of the decision to shorten the war. My father's orders were changed to the Phillipines. Later he went to Japan as part of the occupation force.
Do I regret the bomb? No. I regret that it was needed. Based upon the behavior of the troops on the islands we took, it was likely that many American and Japanese lives were saved, apologists to the contrary.