Very mild white patches. It be vitiligo?

Dear Dr, lately I have started noticing that at certain areas of my face have become very mildly pale. They can't be called white, just one or two shades lighter than the surrounding skin. I asked my brother to comment on how noticeable these 'patches' are, and he said he could hardly notice although if you look closely they are certainly lighter. One such roundish patch is near the right side of my mouth while a couple other are on the left side (few mm in dia). One tiny line is also coming up from upper lip. Could it be vitiligo? Although I know vitiligo spots are much whiter and prominent as my mother has them. I'm extremely worried, tried finding causes of such subtle patches online but can't relate to any reasons yet. I have hypothyroidism which was in normal range when I checked a few months back. I'm getting it checked again today along with vitamin b12. Also have mild rosacea. Please advise what these mild whitish patches could be as I can't visit a doctor for a few weeks.