Refractometer--am I doing it right?

Hey all, just a quick question to make sure I’m converting the information from my new refractometer correctly.

Using the first calculator on http://www.northernbrewer.com/refractometer-calculator/, I found I had a 1.082 original gravity at 19.76 Brix (read that before I pitched the yeast). Today, I got a 12.2 Brix, and used the second calculator on that page to get 1.028 gravity (and just over 7% ABV).

Did I miss any steps? Love how little beer the refractometer uses, but there seems to be a lot of conversions to manage.

Thanks for taking a look!

-Jeff