Give some stream of consciousness and then the answer. The germinal stage refers to the time from fertilization through the development of the early embryo until implantation is completed in the uterus. The germinal stage takes around 10 days. During this stage, the zygote begins to divide, in a process called cleavage. A blastocyst is then formed and implanted in the uterus. Embryogenesis continues with the next stage of gastrulation, when the three germ layers of the embryo form in a process called histogenesis, and the processes of neurulation and organogenesis follow.

Based on this passage, what is the first stage of an embryo?
To answer the question, consider the following: The germinal stage refers to the time from fertilization through the development of the early embryo until implantation is completed in the uterus.
Therefore, the answer is The germinal stage.