Peaple have my pictures and videos that i NEVER send to anyone

a guy on my sisters snapchat texted her and told her that he had my pictures, and the problem is i never sent these pictures to anyone, as a matter of a fact they were deleted off my phone. i honestly dont know what to do, my password is secure and im not sure how this even happened. can my phone be hacked ? i havent given my passwords out to anyone, and i honestly dont know how he has my pictures.