How fast do u dilate?

Ranise • Baby blue

So i went to the ER today because i had some bright red blood and some mucus. They checked my cervix and im only half a cm dilated. Which is great cuz I'm only 30wks and 3days. But I am a little concerned on if i am dilating already how long will it take before I go into activate labor?

Should i check my cervix at home as well? Just in case i have dilated more?