My photos not in my SD card

Hi,

I took a bunch of photos, but when I tried to transfer from my SD card, i realise that none of my photos are in the card. This is so bizzare.
I put the card back into the device, and when i look at my phone under ALL and Camera, it shows that my photo is in there.

Why can't i detect it when i insert the SD card into the computer, or when I link up the camera to laptop via usb wire.

Sometimes when I link up via cable my camera and my laptop, the camera starts making a non-stop beeping sound. Is there a problem with the device?

Thank you!