Anyone else randomly gotten rounds of the shakes at the end of their last trimester? Half the day…

Anyone else randomly gotten rounds of the shakes at the end of their last trimester? Half the day today I just randomly start trembling/shivering for up to like 10 min at a time and then it stops for a while. Then repeat. I know it isn't my blood sugar and I'm not cold. I'm a little freaked out by it, because I know what it isn't. Oh, if it makes a difference I've been told I was in early labor for just over a week? Anyone got any experience/ideas?