From the main FAQs:

"9. How many computers can I use VEGAS Pro on?
You can use VEGAS Pro (14.0 and later) simultaneously on 2 devices. There are 2 ways to deactivate a device so you can activate a different one:

Visit your MAGIX account > My Products > Show More Details > Deactivate. This option can be used only once a month.

From the VEGAS Pro Help menu choose Deactivate the Software on this PC. This option can be used as often as you wish. An internet connection is required."

Check you MAGIX account to see your licenses .