First, I refer you to a couple of references: Genesis 31:25-35 (emphasis on the last verse) and Christine’s post about feminine blood.
Second, I remind you that a great deal of Moses’ Law pulled in existing ancient custom and belief. Laban was unwilling to put his hands on his daughter’s camel saddle — which made a pretty convenient chair for folks traveling without furniture — as part of Ancient Near Eastern custom and Laban’s pagan religion, too.
Maybe you already understand that a lot such ancient law and custom was a simple matter of survival in Ancient Near East (ANE). Some of those people lived very long and healthy lives without the modern obsessions with bathing every day and dashing all manner of toxic chemicals on themselves so they would smell nice. They smelled like humans. It’s not that they were unsanitary people, but they handled sanitation differently. It’s a simple fact of life that in the semi-desert lands of the ANE, a menstrual flow constitutes an easy vector for infection unless it’s contained.* Not so much a threat to her own health, but once the flow is outside a woman’s body, it has to be properly handled. In the minds of those people in that part of the world, it had to handled like something that had died. Shed blood was sacred.
What may not be obvious is that there is another element to this whole picture: There are some places where men don’t belong. In that sense, it’s something sacred, reserved for women only. Men rightly back off and treat it with some reverence. Thus, it’s not because Laban was repulsed by some imaginary nastiness of women in menstruation, but he was respectful enough to avoid messing with it, despite the high likelihood she was lying. Reverence for God includes reverence for His Creation.
Western culture is deeply confused and perverted about a lot of things. This is one of them. Christine in her post refers to the weirdness of women both aping and denigrating men, when the divine design was the utter necessity of male and female working in harmony, doing those things each does best to preserve moral stability in Creation. Western Civilization took all the worst ideas about reality from the European Germanic tribal roots, and the conflict between the sexes is one of those very bad ideas. It’s strongly tied to the obsession with the individual as a free agent versus the biblical understanding that we are all one in Creation. The Western way leads to isolation and a host of perversions.
So with our ultra-sanitary lifestyle, there’s nothing inherently immoral about sex during menstruation if the woman finds it comforting. Leviticus 15 is very easily misunderstood without the cultural context of the ANE. The high degree of ritualization was simply their way of provoking a moral sensitivity. But it fit their lifestyle, and a great many elements of Moses and ANE culture simply have no place in our world. You must learn to see through the Old Testament law to the character of God Almighty.
The very thing that Jesus condemned was mindless legalism, seizing upon the words of the Old Testament without any measure of contextual moral discernment. The Law of God is no longer written in stone, but in our hearts. It’s meant to be alive. This is why we teach that Jesus is the Living Law of God. God’s truth is intensely personal because it’s alive in itself.
* Note: Christina insists that a healthy woman’s menstrual flow isn’t a threat to anyone. My intent was to point out how the Hebrews and other ANE folks approached the matter.