Great going on the tuck and roll!! Nicely done!

The issue of whether there's something more seriously wrong is kind of a matter of degree: What does the pain feel like? Where is it? Is it consistent? Is it sharp? From what you have described, like sleeping on it wrong, my gut says nothing major is wrong - but if you have any doubts you should see someone to be sure. (As you'll see, I don't necessarily follow my own advice...)

My last major (road) crash was the end of November in a race in Tucson. I still have occasional pain in my lower back with occasional radiating pain down one leg from this crash. Mostly when I climb. I know that there's some inflammation there in my back, and when it acts up the advil knocks the swelling down. So I take advil on and off to treat that. If I am going to be riding for a long time, I take it as a preventative measure. I'm kind of pig headed and stubborn about it and I did not go see anyone. I know that it is getting better over time - it's really MUCH better now.

But a crash injury can take longer to heal than a sore muscle from workout injury.