I'm paranoid about my face being altered due to becoming infected. So does it start to change when you catch the vampire disease? Or do you have to become a full fledged vamp first? If the message comes up "You feel a strange thirst as the sun sets." or "You feel weak as the sun rises." and I then cure myself am I safe?

Thanks.

Your face does change but I don't remember when exactly. It gets a more skinnier look.

When you don't want to be a vampire anymore you can head to Morthal and speak with Falion. He'll start you on a little quest and by the end you'll be cured. You can do this quest as many times as you want and your looks will go back to normal once you're cured.

Do they go back to how they were before? Because I remember in Oblivion even after you get cured your looks are ruined.

yes, and you can contract the disease again, and it doesnt actually affect the face model much if at all, it affects the skin, which becomes a little paler and... blotchy.

EDIT: This is without Dawnguard. Still haven't played Dawnguard.

ALSO AN EDIT: And the re-contracting it might also be a Dawnguard thing, I've never bothered trying to get it after it's cured.