My fifth week was just a physical exam to see if my uterus felt pregnant (i.e. during the fifth week, apparently your uterus is more circular than usual and down lower, so the dr can tell whether it is normal or ectopic). My first u/s is scheduled for tomorrow, which is when I turn 10 weeks. Some doctors like to do the first u/s around 8 weeks, but a lot of time the baby is hiding during this time, so you can't get the heartbeat. I believe that is why my dr prefers to wait until 10 weeks ... the odds of hearing the heartbeat are much higher.
Best wishes!
Depends on the country you live in. In North America for sure at 18/19 weeks but also around 6-8 weeks if there is any kind of concern about implantation or at your personal request. In some European countries it is done every visit because doctors have the ultrasound equipment in their Ob/Gyn offices and need to pay it off...