MacBook Pro (13inch, mid 2012) iPhoto photos
If you've been using Time Machine to backup your MacBook Pro to an external hard drive then yes, your photos will be backed up as long as you haven't specifically excluded them from being backed up.

To check:


Go to System Preferences > Time Machine
Click on the Options button at bottom right
In the window that appears, make sure that your iPhoto Library is not listed and therefore excluded from your backups


As long as it's not listed, you'll be fine.

Another thing you can do is to also manually backup your iPhoto Library. The iPhoto Library is located within your Pictures folder.