Help!

I'm 29 weeks pregnant, and I did something really stupid, I tried moving my machine printer at work that is over 30lbs (I know I'm really dumb for doing so) it's quite heavy. I felt something pull under my belly and pop! I'm not bleeding but I am cramping pretty bad! I'm scared I don't want anything to happen to my baby but I'm unsure if I should go to the E.R or not?