I Have Increasingly Bad Pain In My Lower Back, Kindly Help Me Out

I had a minor wreck running up on a curve and over the end of a guardrail like a month ago(several throughout life!) and I was having a bad pain pain for a few hrs later. I didnt see a dr. or anything. And then it went away and all of the sudden about 4 days ago now, I have increasingly bad pain in my lower back, it feels like where my spine ends and hip begins, and its a very sharp pain that shoots down my left leg when I walk or stand for longer than 2 or 3 minutes. And when I sit up for a while. I'm also about 10 weeks pregnant , wondering if thats the cause. But it is exrutiating as well as very annoying. I'm wondering besides the E.R. what I can do for temp.releif. Heating pads, hot tubs and icyhot patches no longer help.