I went to 4cm in 30 minutes later and had my baby same day.
You could stay a 2 for a long time. You could even still go passed your due date. You should get ready for baby though.
Not necessarily. Some women will be a few centimeters for weeks and not give birth. It really just varies from person to person.
I'd start getting everything ready though since it's not too long
Should probably start buying stuff then.