Recommendations. First, get anything still on the card off of it. Then reformat the card using your camera. (There should be instructions with the camera on how to do this.)
If the card reformats correctly, you should be OK, but take some pics and try the card in other devices to see how it behaves.
One more thing, these cards have "locks" to protect data, and they can easily be flipped to the wrong setting, causing odd behavior on different devices.
Note, too, that these cards do not last forever. Flash memory goes bad after a while, and once this happens, it's time to ditch it and buy a new card. I know you said it's a new card, but like any modern microelectronic device, there is the occasional "crib death."