Sectoral heterochromia?

My son has had blue eyes since birth, however, one section of his left eye has always looked a little different/ had a slightly darker hue. However, as he gets older, the color difference gets more and more pronounced. (This photo’s coloring is edited a bit to highlight difference). He is now 2. Does this look like sectorial heterochromia or something more concerning? We can’t get into a specialist until May.

My son has had blue eyes since birth, however, one section of his left eye has always looked a little different/ had a slightly darker hue. However, as he gets older, the color difference gets more and more pronounced. (This photo’s coloring is edited a bit to highlight difference). He is now 2. Does this look like sectorial heterochromia or something more concerning? We can’t get into a specialist until May.