A woman can check her cervical mucus by wiping with clean toilet paper, or by inserting a clean finger into her vagina and reaching toward the cervix. There is usually more cervical mucus if checking after a bowel movement.
A few days after a period, when approaching ovulation, amount of cervical mucus increases, becoming wetter, stretchier and more slippery, looking and feeling like raw egg whites. This "egg white" cervical mucus is the most fertile, as it allows sperm to swim easily into the cervix. Cervical mucus becomes thinner and more watery close to ovulation. This allows sperm to move into the cervix. Creamy cervical mucus can be a pearly white or creamy yellow. It's thick and feels like lotion when rubbed between your fingers. It is considered non-fertile because it makes it more difficult for sperm to reach the egg.
Closer to the period, cervical mucus becomes sticky or tacky. This is the least fertile cervical mucus, as it's hard for sperm to swim through it. It's thick and lumpy, and feels like gluey paste.