No worries! It can take up to 24 hours for an egg to be fertilized. From there the embryo needs about a week to work from the ovary through the fallopian tube and get to the uterus.
The term thagomizer was coined by Gary Larson in humor, in a 1982 Far Side comic, in which a group of cavemen in a faux-modern lecture hall are taught by their caveman professor that the spikes on a stegosaur's tail are so named after the late Thag Simmons.
The arrangement of spikes originally had no distinct name; the term Thagomizer was coined in 1982 by cartoonist Gary Larson in his The Far Side comic strip, and thereafter became gradually adopted as an informal term within scientific circles, research, and education.