1st doctor's visit - How far along?

Samantha • Mom to Greyson 👦🏼 💙 • Baby girl 🎀 due March 2019
I'm going for my first doctor's appointment next Thursday and I should be 7wk1d according to this app. How common is it for that to be how far along you actually are?? I'm just hoping I can see something on an ultrasound when I go. ☺️