Three stages of purification are necessary to end the status of nidda:
1) A hefsek tahara (see next section)
2) Seven clean days without blood
3) Immersion
Generally, a woman can begin counting seven clean days only after four days of bleeding. So, the couple must separate for at least 11 days – four days of bleeding and seven clean days. Often, a woman’s period lasts five to seven days, in which case the separation is longer. If a woman has a short period and stops bleeding after one to three days, she may clean herself well internally, perform a hefsek tahara before sunset, and start counting seven clean days.
