Taking forever to run a full scan

Hello I don't know if there's anything wrong with the scan . I decided to run a full scan as of this time as you can see it's been running for over 7 hours and only had less than half of my computer scanned it's telling me I have more than six hours left till has done it's a full scan and I started it manually I have never seen a program end up running for as long as it's doing is there something wrong with this or is it just weird it's not the first time it's done this every time I run a full scan it takes over 12 hours two complete I don't think it's supposed to do that can somebody please help me. This is the only antivirus I have in this computer.