Exercise at work

its counted in your daily activity level (i would probably opt for lightly active, as youre not really walking around all day). regardless, its not counted as exercise.

This^

Logging these daily type activities can lead to double dipping. Upping the activity level will give you a little bump.

What they all said. If you're really concerned, you can purchase an activity tracker to monitor your steps throughout the day (though I would advise you to get a clip one, as the repetitive arm movements can skew a band's recordings and make it seem like you're burning well more).

If you need to get more movement into your day, you could take a walk on your breaks. I have a little walking route that I've mapped out at work. On my 15's I go and do one lap. On my lunch I do 2-3 laps. Even though I'm on my feet all day as a nurse, it helps to get out and take those extra walks. I also take the 8 flights of stairs a few times per day instead of the elevator. You could even walk in place at your register when you're not busy. The endorphin boost will make it easier to deal with the public