Hi, l&h, and welcome to Apple Discussions. Don't worry: yes, you can recover the pictures from the memory card if you haven't already used it to store new pictures. You'll need a card reader (about $10 if you don't have one already) and you'll need to download the free demo version of one or more of the following image-recovery utilities:
PhotoRescue
MediaRecover
CardRaider
Run the demo and see what it says is recoverable. If you find that all your photos are there to recover, pay for the full version and use it. Just save the pictures to a folder on the desktop of your hard drive, then import them into iPhoto from there.