Progeston or Estrogenol Contraceptives?

Progeston is really the effective molecule. Some low dose pregestin only methods do allow for ovulation because the systemic dose is so low. But progestions also have local effects on the cervical mucus and motility of the pilopian tubes, which are responsible for sperm transport. And so some of the most highly effective contraceptive methods that rely on pogeston actually allow for Ovulation.