I never had any symptoms, and I had a three-week window, before I started the Patch.
Cramps however, were awful. They’re still bad with the Patch, but I only do the fetal-position-can’t-sleep thing the first night instead of every night.
Already In Use, unfortunately most of these symptoms are typical.
The migraines mentioned by others are less typical, but still fairly common. Every woman in my family gets them, with the exception of myself. I took the migraines one step further, and have hormonally-triggered epileptic seizures.
The mood swings, cramping, zits, and all that other stuff, though, is pretty much par for nearly every female’s course, to varying degrees.
The best advice I could give you on how to be considerate during this time (besides catering to our every whim, of course ;)) is to just understand that we’re really not making this shit up. It’s not “all in our heads,” as was commonly believed until pretty recently. And please believe that really, we don’t want you to fall of the face of the earth. It’s just the hormones talking. 
PMS is quite real. I don’t get it every time, but when I do, watch out. I get extremely irritable. If I ask you a question, you had better not say “I beg your pardon?” more than once, or I will be pissed. If you ask ME a question, it had better be succient and clear, and there better not be follow-up questions.
Don’t tap me on the shoulder.
Don’t make fun of my hair.
Don’t ask me to do crazy-ass favors.
Don’t insist I eat when I say I’m not hungry.
If you follow these simple rules, all will go well.
I can always* tell when the PMS is coming on. I’ll be in the grocery store, and some little old lady’s cart will block mine for a minute. On the surface, I smile politely and say “excuse me.” Inside, the thought process is more like: “Jeeeezis, lady, what the FUCK? Is it possible you think you’re the ONLY PERSON IN THE GODDAMN STORE? Do you not have ANY concept WHATSOEVER that someone else just MIGHT want to get down this fucking aisle before the next ice age sets in? And could you POSSIBLY move any fucking SLOWER? Dear gawd, I hope someone shoots me before I become the kind of selfish, careless, thoughtless ASSHOLE you are for leaving your cart two inches further into the aisle than was absolutely necessary.”
I am coherent enough never to act on these out-of-proportion thoughts, but when I realize I’m plotting the murder of an innocent person for no good reason, I think, “Whoops. PMS. Time to go back home and hide in my room for three days for the good of the public.”
(*Again, this month, no warning whatsoever.)