Flaxseeds and PMSing?

when I have 1 tspn of flaxseed days prior to my merstruation on even on the first day I don't feel any of the physical symptoms when PMSing and even the psychological and hormonal changes gets milder, so what is it about the flaxseed that does that? I heard it contains feminine hormones but does that makes unhealthy to consume specially before that time of month?