Keep in mind the port is sutured down to the muscle under it, check to see if the port is hyper mobile and make 100% sure its not acting like it wants to spin on the end of the line (don't go giving it full twists tho.) A quick check with the nursing staff who maintains your port wouldn't be a bad idea if your really worried about it. Most bad ports come with systemic infections, or the sutures have come up and the port now just "dangles" on the end of the line. Which you don't want it applying torque to the vain if it does start spinning.