fetal fibronectin test anyone?

Shayla • Married to the man of my dreams. We are expecting our first child after months of trying and miscarriages
as anyone has this test done and it been positive? Had it done today and won't have results back until tomorrow sometime. I had my cervix measure a week ago and it was over 3 and half and now my cervix has shorten down to 2 something. I am only 29 weeks pregnant. So nervous. Anyone been through this. Any advice? What did the doctors do for you?