Radiating pain is often caused by a pinched nerve or discogenic disease.... best to be checked. But.... that would be MY guess.... but I am NOT a doctor. Good luck.
My money would be on endometriosis. Although another possibility would be an ectopic pregnancy.
If you've recently had surgury it could just be adhesions. I say "just" because they're not usually health threatening, but painful nonetheless.
It could be a heart problem, back problem or even a gallbladder attack- I had THE worst pain ever when I had a gallbladder attack- & it was in my back- it hurt to BREATH even, for 8 hours straight, only thing helped was kneeling on my bed with my arms like a pretzel on my pillow & my head resting on my arms- now i have to avoid fats- only eat fat free or under 5 grams fat per meal- or I'll have one of those attacks again & they are worse than childbirth- pain wise.
Then don't ever move again. I suspect it's a lower back pain.
Get to Doctor ASAP. Could be a number of things.
You probably pulled a ligament, but there is a chance you are starting to experience some of the more advanced stages of appendicitis... either way, I'd go see the doc.
I honestly wasn't sure, so I didn't want to exclude the possibility, and just in case, wanted to exercise the potential importance of going to the doctor just in case, and if I was wrong, best case scenario, I was wrong, and you just pulled a muscle, or ligament, or just have a bad case of gas.
No idea but please see a doctor soon.