Hi Jess and welcome,
I concur with bdrey. I just want to point out that formatting is different than erasing. I take a lot of photos and format my card at least once a month.
The prices of memory cards have dropped considerable the past few years so do consider getting a new one if you current card is not on warranty.
If you get a new card, format it in the camera before using the first time.
Related information ~ Formatting and erasing memory cards:http://www.digicamhelp.com/accessories/memory-cards/erasing.php