Cervix open and I am 21+3 weeks.

Snow
So my doctor told me that my cervix is open but that everything else is close and that the baby seems to be secure. Now I am scared.. Isn't the cervix suppose to be close while preggo?  I told him well I do feel a lot of pressure down there when I sit to pee and he said, just come in to the er if any bleeding happens. I am constantly now thinking... Is this a miscarriage about to happen?! Anyone else had this and had no miscarriage? This is my second pregnancy.