I have what I can describe as cramps around my lap band port. Why?

There a several reasons why a gastric band port can hurt, lets start with the fact that the port is rigid and the tubing the connects the port to the band although flexible is semi rigid . If the port area hurts, specially related to movement, it is commonly caused by a shifted position and the tubing proximal to the port and the port it self, can poke the muscle layer generating pain. If the port is very superficial and you get pressure from a belt or are constantly pressing the port (for example siting and rubbing the area against the edge of a desk or table this can also create pain). Other causes such as infection or foreign body reaction are usually accompanied by skin color changes or inflammation around the port area. An ultrasound of the port area can help figure out what is happening and in many cases pain disappears with port repositioning.
AMG

HelloThe best recommendation is to contact the doctor who perform the procedure, it's for your best if the doctor check on you to prescribe medication.
In addition to other criteria such as medical indications and safety, behavioral health assessments, and so forth I recommend that you go to your certified doctor so he can guide you and do the check up necessary to assist you.
My  Best Wishes,