ibrahim,
was this the first time you tweezed these hairs? I used to tweeze thick hairs that were growing on my chin, and the area got discolored like you say. that sometimes happens on people with darker skin tones with repeated tweezing.
The good news is that it eventually fades. It's important not to let the area get suntanned, because you'll just make that dark area darker. So put sunscreen in that spot.
susie