You plug your charger into your MacBook and discover that it's not charging. Don't worry, it happens, and sometimes you can fix the problem without a trip to the Apple Store of buying a new charger.
There are a few ways to tell if your MacBook is charging
I've seen a few issues that can affect charging.
Hold down the Option key and click on the battery icon in the menu bar. This will show you the battery status.
Since the charger itself can experience a tough life, it's a good idea to carry out some checks.
I'm afraid it's either time for a trip to the Apple Store so a genius can take a look at your MacBook, or you can take a chance and try a new charger (if you don't have access to a spare to try).