I Have Severe Pain On The Tight Side Of My

I have severe pain on the tight side of my leg, halfway up my ankle and calf. It is extremely painful to the touch. Now, it looks as though the painful area has sunk in. There is a crease where the pain is and it feels very hard. It looks different from the Left side, I went to the doctor and was given an ultrasound to rule out a blockage, however, because of my size, they were unable to read from my knee down. The pain iOS not going away and seems to be getting worse. The area is only slightly red. Should I go to the ER? It doesn't seem to be going away. My foot is also swollen, but zit has good color and I can feel all of my toes. I'm worried.