Strange pullet behavior - not laying yet but any day

I have an EE pullet that was 19 weeks old Monday. The other day I heard her making some kind of commotion & was gonna see about her but she came running close to where I was. I thought she may have gotten pecked by one of the older hens or trying to get away from the rooster or something...didn't really think much more about it until now..

She is normally chasing after the 9-week olds & running them off, but today I noticed her sitting in the corner of the yard by herself dustbathing. I was on the porch. All of a sudden she made a loud noise & was trying to walk to where the other teenagers were, but it's like she kept walking funny & squatting down (didn't seem like typical just squatting)....more like a squat like "Hey, I've got something hanging out my butt & I've gotta get this out!" according to the way she was walking. Every few steps she would do this squatting thing & make a sound. One of the other hens even came up & looked at her butt. I wasn't sure if the sound & walking funny was her in pain or what.

I went & picked her up....didn't notice anything unusual but also wasn't quite sure what to look for. She flew out of my arms & has been walking around like normal since.

I wondered if it's her about to lay & she might have felt something weird & didn't quite know what it was or something. Then, I worried (excessive worrier) that she could be starting to get egg bound or something on her first egg, but I wasn't sure what signs to look for on that.

What could it be?