Does your cervix shorten?

I have been checking my cervix daily for about five months since we have been TTC. Has anyone noticed that during some parts of your cycle that the cervix is very short? I know that an infertile cervix sits low, but mine is low and quite short-compared to what I normally feel as low and long. I am on cycle day 23, with an average of 30-31 day cyles. I am 5 DPO