Red Hard Area On Calf Could This Be A Clot?

Could this be a clot? - red hard area on calf

I had some leg pain for several weeks in some other points. Everyone in my left leg and the other is in the rear leg behind the knee, calves and 2 points in my ankle. I thought the first time since the sciatica in my butt was sore. Last night, I noticed that my ankle was swollen where it hurts. It is not like me to hold water, but more than one node. Today, this area is still swollen at the tip of all ankle swelling. Now I have shot in there. My concern is that this can be a blood clot. Do you want me to the emergency room or can wait until Monday. Because if it is not red or hot, but surely Likea back pain and bow at the ankle, which is about 2-3 inches around and raised little.Thanks