Cervix issues??

Ivy

Went to my 20 week checkup and the doctor kept asking me if I have been feeling pressure and if I ever had any procedures on my cervix. Right then I knew something was up... they told me that my cervix is on the low end of normal and I have to go back in two weeks to see if it has gotten shorter by then. Has anyone experienced this and if so should I be worried about my baby? They said he looks good but did this cause early labor for anyone else?