In the first 4-10 days of embryonic development, where does the energy come from to drive the process

The first 4 to 10 days of embryonic development the energy comes from the fertilized egg to drive the process.

The process where baby comes to life begins with an utterly ordinary event. During the last period before conception then the groundwork of pregnancy is being laid.

The previous we have endometrium which is the uterine lining. From there then follicle stimulating hormone takes over.