I am female and sometimes I need to talk about the biological things that come along with that for most of us female folk. I recently came up with a Nevashi phrase for menstruation: to have high tide. This uses "ca" (bodily functions and speech) with "def" (to have, hold, contain, etc)-- a fairly rare combination.
Ci def im ececian. She has high tide. (Insert your favorite euphemism for menstruation here.)
You can blame Alabama for this, by the way. A Crimson Tide bumper sticker on the car ahead of me at a stoplight started this train of thought.