As long as it doesn't HURT, that's not uncommon. I often shake when stretching; although make sure you aren't trying to stretch TOO far. Don't bounce, either.
Writer, mother, wife, and breadwinner. I love to run, but running doesn't love me, so I'm switching to my low-impact bike.
I'm not pregnant, just fat: My blog. fatnotpregnant.blogspot.com/
| current weight: 190.6