Everything has an aura.
To practice seeing yours more, I suggest using a blank, white piece of paper. Hang it up and then put your hand infront of it. Look past your hand, and focus on the paper, whilst seeing your hand in your periphreal vision. You will start to see a transparents outline of your hand, as you did. But if you blinked, I doubt it was your aura, because once you close your eyes, you break all concentration. Try it again, but do not blink. If you do, just try again.
You can also replace your hand with objects or get a friend to put their hand against the paper to see if you can see their aura. You can strengthen your aura through meditation and cleanse it in many ways, like taking a hot shower and visualizing the negative energy washing away and out of your body.
I hope this helped.