Is my Phone's Files Corrupted or have Virus?

I tried charging my phone (Samsung Galaxy y) in my laptop yesterday and didn't know that my files are still working in my laptop. My sisters just unplug my phone from the computer. And tody I just saw my photos and videos were gone but my music and my .pdf files are still in my memory card. Aftet finding out that my photos were gone I got frustrated because the photos of my friends and pets were all gone. Is my phone corrupted or the virus' fault? If its corrupted I'll try to reboot my phone.