Confused about cervix

[Angel022605]

Is it normal to have a cerxix that's constantly firm? For the past few months my cervix had been firm before and after AF, before, during, and after O. However the opening varies. Just after AF it's partially open and low, then during fertile period it's high and wide open and stays wide open until about a week before AF then it returns to low and partially open. But one thing remains.........it stays firm no matter what part of the cycle I'm at. Is this normal???