Self-observation of the cervix to distinguish days of possible fertility.
Keefe
E F
EF
D001695:Biology; D003267:Contraception; D005193:Family Planning Services; D008598:Menstruation; D010061:Ovulation Detection; D012098:Reproduction; D012106:Research
Biology; Cervical Mucus Method; Clinical Research; Contraception; Family Planning; Family Planning, Behavioral Methods; Fertile Period; Natural Family Planning; Reproduction; Reproductive Period; Research Methodology