I Fell On Ice While Snowboarding. I Hit My Sacrum

I fell on ice while snowboarding. I hit my sacrum quite hard; it felt like I was going to loose all bodily function. Eight days after the injury, I had a dull ache in my sacrum while walking, and a sharp pain when I sat a certain way. The pain is slightly greater on my right side. I went to the doctor at that point. She prescribed muscle relaxants and pain killers. I haven't taken either, I'm just trying to take it easy. Today (two days later) I woke up to constant pain in the back of my right calf. Since I didn't do anything active recently, I'm wondering if it could be related to my sacral injury. If it is related, should I be concerned?