HELP!!! so worried!!!!!

Brittany • Mommy to 5 angels! And mommy to TWINS :) surprise baby on the way!
So I went to the doc yesterday and had to get sent over to the specialist they said my cervix is not even half the length it needs to be and is already thinned out as if I was 35+ weeks I'm only 17 weeks!!! He said babies(twins) look great but I'm on strict bed rest has anyone else had this happen !?!!!