Severe Pain In The Hand After Having An IV Insertion. Painful Lump Formed. Worried About Clots

I was admitted to the hospital Friday morning and had an I.V. inserted in my left arm in the bend. During my two day stay, the site was painful but I attributed this to the fact that I'm left-handed and kept moving that arm out of habit. A couple of hours before I was released from the hospital today, I asked them to please take out the I.V. because it had become very, very painful. They did so, but the pain has not subsided. In fact, it has gotten worse and is now radiating down the length of my arm. Additionally, I've developed a large painful lump right above the I.V. site. I called and spoke to one of the nurses at the hospital and was told that since I was no longer a patient and she could not actually see the lump, she could not give me any advice. Her suggestion was to call my regular Dr. in the morning. After reading various "diagnoses" on the internet, I am not sure if it's something as minor as irritation of the vein or something more serious like a clot or infection that require immediate treatment. Any advice you can offer would be appreciated.