breast fluctuations

does anyone know a scientific answer to this question that has been
gnawing at me for some time now?

once every couple months (with no noticeable regularity.... but it's usually
before i get a period. not every period though),
my boobs plump up almost another cup size, for maybe 3 or 4 days,
and it's really awesome, so awesome i just lie in bed and cuddle them,
but then they return to their normal, not entirely plump state and stay
that way for awhile.

it seems natural enough but shouldn't it happen every month?

so i wonder if there's anything in my diet or lifestyle i can do
to make this happen with more regularity.
drink more water?
is water retained in the breasts if you drink a lot of it?
cause i really need to drink more water anyway....

or could it have to do with eating a lot of soy at one time, possibly?
i go through phases of eating a lot of soy, then not eating much soy.

i don't drink cow's milk, so i'm not getting any artificial hormones..
i don't take birth control either, so i know it's not that.

does anyone else experience what i'm talking about?

I have the same boob thing. When you figure out the secret, send it my way. My boobs look pretty awesome right now, but I know they'll be back to their normal little size in a couple of days. It makes me sad.