You might feel a bit nervous for your viva. You might even feel that for submission. It’s understandable. Your thesis, your viva and your PhD are all important, so of course you could be a bit nervous.
At the same time you could be a bit confident.
A bit certain of what to expect.
A bit sure of who your examiners are and what they might want.
And more than a bit talented, definitely good enough, to pass your viva.
Nervousness can make you a bit uncomfortable. Try to put that into perspective with everything else you can be, feel and know for your viva.