Geragos:"Blood can't be dated, it is Laci's bed and she could have cut her legs shaving or gotten cut in the kitchen"
I would have to suggest that there would be a difference between blood splatter and drops from a shaving cut.
But they can analyze it for hormones! I heard they can tell what level of pregnancy hormone was in the blood. That's pretty darn close to being able to date it!
UH HUH and of course we know that Laci would have just "left it there" don't we Meg? I can't quite see her shaving her own legs at that stage of pregnancy anyway. I sure couldn't get over my belly to shave my legs.