I get stomach pain intermittently and I'm not sure what it is (maybe HAE)

Hi,
I get awful stomach pain ever few weeks. It last about 5 days and is a very severe aching pain. My family has history of crohns but I have tested negative. I have spent a lot of time researching however all i have found is about HAE and it being something mental as I have been in to the ER and they did bloods and ultrasound to test me for the usual stuff. Im not sure if this is relevent but I get hives for no explained reason in burst every so often. Aswell as this as far as i am aware it has nothing to do with my menstrel cycle as it started before I started menstrating and even now it does not happen at any time relating to my menstrel cycle