Shaking while nursing to sleep

My baby today started doing a little tremble while I was nursing her to sleep it only lasted a few seconds but I pulled her off me and got her attention because it freaked me out. Has anyone had that happen? I don’t know if it was shivers or what. Since it’s the weekend I’m going to see if my doctors office will take me in tomorrow for the weekend clinic. Just wanted to see if anyone’s experienced this before. Other then that she’s been completely herself all day.