Your cervix will change position during the day. Therefore it is best to check it once, at the same time every day. Some women (me included) stop checking after ovulation is established, because it can introduce germs. My cervix stays high for a few days before and after ovulation, and slowly drops down to a low position before AF arrives.

Charting your BBT is much more accurate at confirming ovulation than following CM and CP and ovulation pains. Ovulation pains are the least accurate!

Your cervix should change position during your cycle. Healthy women occaisonally have an anovulatory cycle. Maybe one or two a year. HTH!