Cervical Position

Can your cervix randomly become soft and open? Mine was soft and open for my entire fertile window but then it became hard and closed again and I'm 4 or 5 dpo and this morning it was high hard and closed and tonight it's low soft and open. What is going on?? Also my CM was really thick ad sticky after my fertile window and this morning and now it's really watery. (Not egg white though) 
Anyone able to give some insight?