1) Don't even think about hinting at “that time of the month.” Seriously. You may be right, but just don't. We know better than you do how crazy our body chemicals make us. If we don't realize that that is the source of our emotional outburst right now, we will eventually, and your trying to rush that process will only prolong it.
But even more than that, blaming all of our tears on hormones just minimizes the real problem . . . and yes, there usually is a real problem. It's possible that your lady just fell apart into torrential sobs over absolutely nothing, but it's not likely. It's more likely that the hormones simply magnified the reaction to a very real problem that deserves very real attention.
2) Don't try to make her stop crying. At least, on a surface level. When I see a teenage boy with his weepy teenage girlfriend trying to make her laugh to stop the tears . . . or, God forbid, tickling her (seriously, do you have a death wish?) . . . I think, “Yeah, dude, she'll think that's cute and appreciate your effort for a while, but be prepared for the blow-up one day.”
Once again, you have to remember that under the apparent hysterics, there is a real problem. When you minimize that problem, you are minimizing her. It's demeaning. I know you mean well -- so does she, that's why she'll put up with it for a while -- but there comes a point where you look like you aren't interested in the whole woman here. You're only interested in a happy, pretty plaything that entertains you and responds to the push of a button. That's not a woman; that's a doll. Buy a doll.
3) Don't try to fix the problem – at least at first. I realize that sounds COMPLETELY contradictory to what I said in my first two points. And here is where I'll admit some craziness on the part of my gender. Men are fixers; they see a problem, they fix it. Women are not men. Sometimes, we need some wallow time. We need to feel the full emotional impact of what we're dealing with and get a grip on that before we can deal with it. Yes, we will over-do it occasionally and indulge in our wallowing to an unhealthy extent (ladies, you need to recognize this tendency in yourself and work on it so your man doesn't have to attempt the dangerous maneuver of pointing it out to you).
But I'll let you in on an important secret: often, when a woman is not able to get past the emotions of a situation and move on, it's because somebody in her life (currently or regularly in the past) has minimized her emotions so much that she has learned to compensate by exaggerating them. She has to over-react to demonstrate -- to herself and to you -- that her feelings are legitimate. That SHE is legitimate. Weird, yes . . . but only to a man.
Your woman would probably welcome your suggestions and insight into her situation, but not until she's ready. Not until she's felt the full emotional impact of that situation. Not until after you . . .
* DO sit with her and help carry the burden. Listen. Hold her hand. Affirm how bad things are. Yes, even if you don't quite understand why things are so bad. I'm not saying to patronize and lie . . . I'm saying take the time to understand what this means to her. Did you catch that key word? UNDERSTAND. Attempt to understand. Women are extremely relational by nature. They won't care to hear your suggestions until they are convinced you really get the problem. How can you fix things until you understand?
This is hard for men; I get that. But let me give you some encouragement: the more you do this, the less you may need to do this. The more understood she feels, the quicker she can get through the emotions and be ready for your assistance in solving it all.
Do I hear an "amen", sisters?