Ultrasounds

So I found out today that I won’t get an ultrasound until 19 weeks. And I’m guessing that will be the only one. I’m only 6 weeks now so that feels like a lifetime away. And because of having a chemical a few months ago I just want to know that everything is ok. I’ve decided I’m going to pay for a private scan but am wondering when I should schedule one. I want to have one between now and the 19 weeks but want to be able to at least somewhat make out the shape of a baby. I’m wanting to have a picture from this one to use when we tell our parents as well.

So when should I schedule one that would be more than just the yolk sac but before the 19 week one?