As I am reviewing my lecture notes from my developmental biology class, I am feeling simultaneous feelings of utter confusion and complete awe. I just can't believe so many of us turn out so normal looking, given how complicated it is to make a functioning fetus from an embryo. IT IS AMAZING! We have neural cells that are able to migrate all over us, make up our skin pigment, gut nervous system, eye color. Our heart starts working after 3 weeks and is a single tube that somehow develops into 4 chambers with valves and the rest of our beautiful circulation system. Our stomach actually internally rotates and ends up on our left side even though it rotates to the right first. To top it off, our intestines actually LEAVE our bodies because there isn't enough room to contain all of it and enter an extraembryonic cavity in the umbilical cord before deciding they want in on the party and excitement that is embryonic development.
Seriously, thank your body, it's amazing. Don't mess it up. Treat it well.