Could also be from baby hearing a loud noise and getting startled mine did that a couple of time's :) and she's 6 days old and perfectly fine
I'm 32+1 and I felt my baby vibrating, or shakin' like he's having a seizure (hope he Isn't!) a few times It scares the crap outta me since that's the only thing I don't know what's goin' on, but cold chills? Huh that's Interesting.
I had no idea of the cold chills, I have been feeling the same stuff For over a lot of weeks and didn't know what it was...
Or cold chill. I had it once with current pregnancy i freaked and thought seizure lol dr told me they could have cold chills on there who knew lol