Charging/battery issue

Just recently, I have had trouble charging my macbook pro. When I plug it in, the lightning bolt symbol does not appear on the battery icon in the top right corner to show that the computer is charging. Instead, there is a plug symbol, and when I click on it, it says, "Battery source is not charging," but it also identifies that the charger is plugged in. I included a picture for reference.

This has been happening for 3 days, but I have never had this problem before. My mac doesn't charge when this plug symbol is there. Any tips?