Very sore hip/lower back - looking for stretches to help

Hello FB friends!

I really tweaked my hip/lower back last night (not sure how) and wondering if anyone has any suggestions of stretches I can do to help relieve the pain. I've been lying on my back w/ knees to my chest and rolling back and forth, and that's really helping, but I was thinking y'all might have some other suggestions.

Thanks in advance!!

Kelli in Oregon