I formed an umbilical hernia during my second pregnancy. I did have the surgery. It's VERY minor surgery. My surgery was done at an outpaitent surgical center, not even a hospital. My doc made and tiny incision inside my belly button, you can't even see it. I was sent home within an hour after surgery. I was sore for awhile..you definately feel like you have had surgery. The hardest part is that they will give you a lifting restriction. Mine was no more than 8lbs for 8weeks. I was fortunate and had a lot of help around. Friends and family basically moved in for a week at a time.
There are two ways the hernia can be repaired. One is with stitches, which is how mine was repaired. They can do this if the hernia is very small. The other is by covering it with a type of metal gauze or screen.
Umbilical hernia's are very common during pregnancy and also in small babies. There is potential for making it bigger; your bowels to protrude, which could be life threatening; also, any small child's elbow or knee in your stomach is extremely painful.
My recommendation is for sure to see a doctor, and probably to have the surgery.