Could Leg Swelling Be Caused By Blood Clotting From The Injury?

Hi: I banged my shin on my left leg very hard 17 days ago on a metal picnic table that was cemented in place. Probably the worse injury to my shin that I have ever experienced in all my 59 years. Within 30 minutes after the injury a large welt appeared on my shin about the size of my kneecap. Since that time the welt has much reduced in size. You can still feel it but cant really notice it anymore. Up until now no black and blue bruises have appeared. I can walk on my leg just fine with only some discomfort at times. However, my leg is still tender to the touch from the bruised area of the shin. Its also tender to the touch from the area of the welt running down my leg about 12 inches below where it was struck. What concerns me is continued swelling or retention of fluids in that leg only. The entire calf, ankle and top of the foot will swell up daily. In the morning when I awake, the swelling has completely disappeared. Obviously elevation of the leg reduces the swelling. My right leg is fine and has no swelling or discomfort whatsoever. I am doing just fine. But, the swelling I would think should have stopped by now. Is this something I should run to the doctor to have checked out asap, or is this something at my age that just is taking a longer time to heal. Could the swelling be caused by a blood clot from the injury? Appreciate your comments and advice. Thanks