Possible hernia?

About a week and a half ago I got my six month old kitten Blackie spayed. I just noticed that she has a lump the size of a golf ball by were her stitches are. I know the females get a little pouch around their bellies when they get fixed, but this doesn't seem that way. So I'm going to hope that the vet is open Monday so I can take her in. Shes playing,eating,drinking, and sleeping normal. Anyone have any suggestions? Thanks

Was glue used instead of stitches? if that's the case it could be an allergic reaction to the glue. That happened to Autumn. They gave her Amoxicillin, and it went away. She never seemed to be in any pain while she had it, she ran around and played.