Yes, I admit, it's that certain time of the month for me as well ... although I don't grow fangs (which probably would be less of a problem and may even mean less bloodshed).
When I stumbled over this picture (also available on a t-shirt), I thought that every woman should have one and wear it a week a month (women will now know what I'm talking about - if they haven't realized it before). It would spare both us and the men a lot of trouble.
And I personally would be grateful for a slight change in the human physique. I'd rather grow fangs and fur and a tail once a month than have that other 'woman's trouble'.