Hard Lump Above C-Section Incision 4w pp

Tiffany • 32/Happily Married/ 9.5 yrs TTC-miracle baby girl born 6/28/16!! Miracle baby #2 due Feb 2018!
Hi ladies, I've had a hell of a month and I'm still waiting for answers! 
- Fever x2 weeks
- Chills
- Headaches
- Pain 
They have been treating me for a uterine infection and I'm waiting to have a cat scan done to check for any left behind surgical material.
However now I have a hard lump in the center of my stomach above the incision. Did anyone else have this???? If anyone could shed some light on what's happening with me with a personal experience I would feel so much better!