Growing pains

I feel certain we all have them, be it physical, or mental. Right now, I'm praying? that's what's causing my son's pain. He didn't really start moving around on his own until after 4 this afternoon. Come bed time, he was walking around with a very slight limp and much less pain. But at one point, he decided he needed to get his father and tried to run... It resulted in a collapse onto his own face. 

I want whatever is causing his pain to be simple and not threatening at all. Praying it's just growing pains, I'm not so sure is the best answer either. Not if they are this  intense. It almost seems like a pulled muscle, there's just no telling.

Right now, we watch and wait. He did get better throughout the evening. Any signs it's getting worse- we head to the ER. If not, we head to the doctor Monday. Prayers welcome. :)