The first time 19-year-old Zoha Qamar went to Friday prayers during her period, the mosque was packed. She had learned from a young age that menstruating women aren't supposed to pray, as dictated by Islamic law and custom.

Typically, they would shuffle to the back of the women's section when the call to prayer began, removing themselves from the area designated for prayer. But on this particularly day, Qamar said, the mosque was so full that even the back had to be occupied by praying women.

"There came a point when I had to leave the room because it was so crowded," Qamar told The Huffington Post. "The fact that there wasnt even space for me to observe was heartbreaking and hard for me to digest as a 12-year-old.