in response to the moment on how pms is an illusion:
pms is not an illusion. it is, however, a completely western construct. if you look at other cultures, women do not regularly have mood swings due to the impending arrival of aunt flow.
western women, on the other hand, tend to get it regularly. although not sure why, most researchers believe it has to do with diet and/or environmental pollutants.
look it up.