…she shall be unclean for seven days… This is the same as the monthly seven day period of uncleanness and corresponds to the seven days of the Creation Week. The potential for new life has gone out of her, and this is a period of rest and restoration before she will begin a new cycle of creation. In actuality, it is often much more than one week–sometimes several months–before a woman resumes her monthly cycles. In the case of childbirth, the normal seven days is extended to at least forty.
Remember that “unclean” does not mean “sinful.” The Hebrew word for unclean, tamay, does not necessarily mean dirty or defiled. It means blocked or walled off. Something which is unclean is off limits. Defilement might cause something to become tamay, but something tamay is not necessarily defiled.