2nd time mommas question

Katelyn • My name is katelyn I am 28 yrs old and the hubby is Charles. He is 31 yrs old. We have 2 boys age 8 and 2. And pregnant with our 3rd -its a girl!
The Dr said it was normal to be 1cm dilated with a previous vag delivery.. I've been 1cm for a few wks now n lost my mucus plug on 3/15 still 1cm