Why can i not find my pictures on my htc anymore

Do you have your phone set to "FAST BOOT" - this often causes pictures to go missing, turn fast boot off and restart your phone (it will take a little longer) and then open gallery... the missing photos should be there.

I used a different gallery app to get around this and still use fast boot
 
I found the pictures after hooking my phone up to the desktop. Haven't had any troubles since. I still don't understand why I couldn't see them, but thanks