I've been wondering about this very thing..... About a week before I get mine everything gets magnified about a 1,000x's. I hate feeling this way! It's an emotional rollercoaster ride through hell. I'm angrier, sadder, more depressed, more likelier to be suicidal, homicidal, promiscuous, cut myself and just act recklessly in general etc. etc.
And to add to my misery my cramps are so awful too 'cause when I had my surgery they found a cyst on my ovary -- Oh joy. Which is probably the cause of my pain.