I Gave Blood Wednesday, The Nurse Did Not Immediately Stop

I gave blood Wednesday, the nurse did not immediately stop the machine after the bag was full and I began to feel pressure in my arm to the point of being painful. Last night I began to feel pressure in that arm and I am experiencing muscle spasms in my hand. Will this go away? What can be done to alleviate the discomfort? I have had a slightly protruding disk in my neck between C6 & C7, which did cause similar symptoms, but not the muscle spasms in my hand.