* It also thickens the mucus at the cervix, thus creating a barrier to sperm moving from the vagina into the uterus.
وَإِذَا لَمْ يُنْتِجِ ٱلْمَبِيضُ بُوَيْضَةً ،‏ فَبِٱلطَّبْعِ لَنْ يَحْدُثَ تَلْقِيحٌ .‏