As a recent convert to Islam I have started wearing the Hijab. However, there are pictures of mine out there, without the Hijab, that were taken earlier. Is that counted as a sin?
You should try your best to get your previous pictures ( with out Hijab) and keep them away from public display. If you could not get all of them, you will not be responsible about them as you were not a Muslim when the photos were displayed. Now when you are a Muslim, it is not sin on you as it is out of your ability to remove it.
Wassalam.