I was talking to a friend recently about all the projects I have going and how it is really a balancing act. Then the subject of overdue payments came up. She said, "Don't you feel weird having to ask for money?" Ummmm....NO. I earned it, they owe it. Quite honestly, very few reputable people in the writing business are out to take you. Don't get me wrong, it does happen, but rarely. Publishers and editors live and die by their reputation. They can't afford to let word get out that they don't pay, or pay slow.
So what do you do if someone hasn't paid by the time stated? I give a friendly professional nudge. I NEVER assume anything good or bad. I see writers at meetings frequently who are complaining about not being paid, or being paid slow. I always have to ask "Did you talk to them about it?" the large majority of the time the answer is no. hmmm. I thought this was a business. And to be in business you have to act like a business person.
Let's take an example:
Let's pretend that you are a florist. You send out fliers that say people can order flowers and that you must be paid by the 10th of the month. Little Boy Blue orders flowers for his mother because she's sick of hearing the horn and you deliver them. The 10th rolls around. Then the 15th. Next thing you know it's the 20th and you are pacing back and forth thinking of terrible places to shove Blue's horn. This is unproductive behavior. Had you sent Blue a reminder, then followed up with a polite and professional phone call, you would have saved yourself a lot of stress. Blue's a busy boy and he's already moved on. A gentle nudge is generally all it takes to save yourself hours or even days of worry and hassle.
I have worked with some very organized and business-like publications and some that are more seat-of-the-pants. Generally some kind persistence really pays in the long run.