according to your findings you are in active labor,
as the cervix
is already 4 cm dilated with full effacement, there is chance for quick progression and also risk of rupture of membranes
, so go to hospital and consult your doctor immediately,
it is not like every woman will delivery only after 40 complete weeks, sometimes labor pains can come early also,
so go to hospital but take proper care while moving there, prefer ambulance if possible.