Fetal development: 5 weeks pregnant

As pregnancy officially starts two weeks before the sperm hits the egg, this embryo just over three weeks old represents pregnancy at "five weeks." The spinal streak is closing and the somites, representing future muscles, are forming along it.

Awww, isn't he cute?

It's a bat.

Embryonic stages

Ten stages showing the development of an embryo up to eight weeks. That's eight real weeks or ten official weeks of pregnancy. Imagine your surprise when a doctor says that you are ten weeks pregnant ten weeks after your last period. That means you are two weeks pregnant, in doctor-speak, when the sperm hits the egg.

If you want information instead of rhetoric about "babies," you can find it here: embryonic stages.