Mucus plug

I'm 33 + 3 I have carried low my entire pregnancy and my doctor has said her head is down since about a month ago . I've had a gut feeling that she was going to come early the past couple days I have gone to the bath room about three times each day and I have felt more pressure down there . Today my mucus plug came out I called my doctor they said its nothing to worry about until I start getting contractions . How long could it be for me to start getting contractions or for my water to break ?