29 days to backup?

I just bought two My passport for Mac products to maintain backups for my MacBook Pro.  I install the utilities and security, and then set up time machine to begin my backup yesterday about 4 p.m.  It is now 9 a.m. CST and I have backed up 130MB of 340 GB and it says it will take 29 days to backup my system.  That can’t even be right - what do I do?

Try testing the drive with First Aid.

How to test a drive for defects or problems on a Mac