Hernia?

Hi there- I have a question for anyone that may have experience with this. My original surgery was 12/05. Three weeks later I had a major set back. A Stictch had broken loose and caused a strangelation and severe sepsis.At that point I had a second "open" surgery where they removed another 26 inches of intestines. I have a very large, thick scar from my breast bone down to my pubic bone. I recovered and have been doing G-R-E-A-T since.  Today, hpwever, I found a lump about the size of a very large grape just to the right of my scar and maybe an inch above my belly button. This lump feels kind of like a an old bruise. I just knid of feels sore, but doesn't rally hurt. Also, I noticed that it is largest when I stand, smaller when I sit, and it disappears when I lay down. Has anyone experienced this? I assume I need tocall my surgeon on Monday, but at what point should I worry?  Thanks,