Checking the cervix is a matter of checking internally, manually and/or visually, and I think it's easier to track this particular fertility signal over time with growing familiarity of your cervix's behavior through your cycles. (It's a very reliable source of PRIMARY information, but plenty of women have no idea about theirs.)
The fertile fluid is slippery and typically behaves like egg white....if you have some on your fingers and pull them apart, it will stretch between them further than your discharge at other times in your cycle.
This is typical or average. Individual women have individual differences and some women NEVER have "egg white quality" fertile mucous. Theirs may be something more like what most women have on their transition days as they near ovulation. But looking for slippery/slick stretchy discharge is a basic starting point.
at 9:21 AM on Jun. 8, 2012