Sahih Muslim
The Book of Menstruation (Kitab Al-Haid)
Book Number: 003 / Hadith Number: 703
Abu Huraira reported: The Messenger of Allah (may peace be upon him) said: If any one of you has pain in his abdomen, but is doubtful whether or not anything has issued from him, be should not leave the mosque unless he hears a sound or perceives a smell.