I'm 32 Have A Umbilical Granuloma, 2 Days Ago I

I'm 32 have a umbilical granuloma, 2 days ago I had chemical cauterization. Going back next week for more. Everything was fine, then today, I experienced a lot of pain. Sharp almost piercing and throbbing pain. I've had pain with it for a while but not like this. Is this normal? Is it getting worse? I have had ct scan and it came back normal. But I still have lots of pain behind my belly button and it's only getting worse. I'm on antibiotics. Could it be something else? Can something be missed with ct scan?