When going for an early pregnancy scan or a viability scan the Sonographers will want to see a few important landmarks. In the early weeks they would want to see an intrauterine pregnancy (in the womb), a yolk sac and a heartbeat amongst other checks.
Take a look at some images that can give you an idea of what you might see at each week in the first trimester.
As you can see an awful lot is happening in the first few weeks so is it any wonder that most women feel exhausted?!