My Cannon digital camera SD card has been missing for a couple of days. But, yesterday, my mom found it for me in the room of my younger sister. I remembered I had saved almost 300 pictures of my friends and families here. However, after connecting it to my computer as usual, there were only 148 pictures. My sister said she had done nothing to this SD card. Whats wrong with it? Is it possible for me to get back all my pictures? Help me, please!