Dilated 3cms without knowing

Hi! I'm currently 37 weeks and 5 days. Today at my appointment at the hospital I came to know I was dilated 3 cms when my gynae did a vaginal check. I didn't feel any contractions that lead me to dilate 3 cms. Is it possible to have no pain and still dilate 3 cms without even us knowing it? #advicepls #pleasehelp #1stimemom #firstbaby