According to the Torah a woman is ritually impure for seven days counting from the first day of menstrual flow. The first day must be included as day one. A day ends and another starts after sunset when three stars are seen in a clear sky. On the first night after seven days she is clean and she can come to her husband again. (My understanding is that the obligation of the mikveh (ritual bath) was added later in Jewish tradition).

I am convinced that the law of the seven days also applies to the redeemed ones from among the nations and must be respected by all non-Jewish disciples of the Messiah.

Jewish law is stricter than the Torah because rabbis have set a protective fence around two very similar commandments so the people won't sin by mistake. That's why there is a synthesis between the regular week of the period (verse 19) and an abnormal flow of blood outside of the regular period (verses 25-30). Therefore, Jews have to count more days each month. According to Jewish law, the seven-day count starts after the day in which blood from the period stopped. After that whole "white week" the couple is allowed and commanded to be together again, after the woman has gone to the mikveh.

It's a good rule not to touch one's wife during the days of her monthly purification. It produces a good result both in character and the emotions. I recommend this practice to all.

May the Eternal give each couple among us discipline and love to be able to live on a high level of sanctification for His glory and for family blessing.

Ketriel