IE and Dilated Cervix

Kapag Low lying ka pwede ka po ba i-IE ng Ob kapag manganganak ka na? In my case nung nagpatransV ako i was 4 mos that time, 0.97 cm low lying gr II ako sinabihan ako na bawal i IE or sex. Now, I'm 8 mos, nagpaBPS ako, low lying pa rin pero di na nakaharang sa cervix ung inunan (posterior in location low lying gr II). Ang kapag pupunta na sa hospital need 5cm dilated correct me if I'm wrong, pano po malalaman na dilated ka na? Based on what I've read, nagpapakita na ng signs of labor like constant contraction, paninigas ng tyan, discharge of mucus plug etc. pero pagdating ng hospital sasabihin di pa dilayed so papauwin lang. May I know how to know if you dilated na and need na magpunta ng hospital?