Effaced ?

Mary

Went To The Dr Today For What I Thought Was Contractions...Im 29 Weeks And 3 Days She Told The Nurse To Put Down That Im 30% Effaced Minus 5 ...🤔 Why Did She Minus The 5 ? and She Said She Can Put A Fingertip In My Cervix But Im Not Dilated ...So What Does Effaced Mean And How Did She Get A Finger Tip In If Im Not Dilated