I came across this site the other day and it is in turn fascinating and maybe a little too graphic for the faint of heart.
My Beautiful Cervix
It is a project done by a trainee midwife who has taken a photo of her cervix on a daily basis through a whole cycle. Yup, check out day 19 if you've heard tell of egg white mucus as a sign of ovulation but wonder exactly what it looks like.
It illustrates really well the stages we all know about in our cycle but can't necessarily visualise - well now you can.
Warning! Don't check this out whilst you are eating.