Thanks for your answers. However, you've created one more question, which is probably a duh one: How do you -rescan?
Assuming you're on Windows, one way to do it is by editing the Windows shortcut that runs Bitcoin. If you open the shortcut properties you should find that the target is something like
"C:\Program Files (x86)\Bitcoin\bitcoin-qt.exe"
Replace this with
"C:\Program Files (x86)\Bitcoin\bitcoin-qt.exe" -rescan
And run it. Afterwards you should remove the -rescan from the link (loading will be slower if you keep it).