Thank you for your question, Samantha.  I chose it because it brings up an issue screenwriters have to deal with all the time.  We can't help but wonder (or you could use the word, "worry" -- or, taking it to another degree, "obsess")  if the producer is going to come across with all the promised money, even if it is stipulated clearly, along with the terms and conditions, in a written contract, which the producer signed.  Okay, brace yourself.  Producers don't always honor their agreements.  They have been known to flake out and not come up with the goods.  Your concern is based on some sort of reality and it is good to do all you can to look out for yourself in terms of receiving your just due.

But worrying about it is not going to help at all.

Not one bit.  Not one scintilla  (I only wrote this piece so that I could use one of my favorite words, "scintilla.") That's not to say that you can't be fully prepared in case that scenario were to take place.  But to worry about it -- or to worry about anything -- is to participate in  the most draining of activities.  Preferably, you've chosen to do business with somebody you sense is an honorable person.  If that not be the case, then the "worry" needed to start a long time before now.  Maybe your first clue was when you took your first meeting (I'm never figured out where these people take there meetings -- but I'm certain its somewhere very important where other entertainment people who have taken their meetings will see them and figure they are important takers of meetings.) and the producer met you in a smoky (now there's a problem right there because all indoor smoking in California is against the law.  That is, if you're in California.  New Brunswick is a different story.  But if you are in New Brunswick making a movie deal, then that could be a problem unto itself.) back room and introduced you to his blonde bombshell "cousin" who he'd like to see as the lead in your  epic, "One Sunday Too Many."  Not to mention that he wrote up the contract on a cocktail napkin.

So, what do you do if you're not going to pass your time worrying?  How do you handle this kind of situation.  Start with the concept that, if you've done and are doing everything honestly as possible on your end (such as honoring your agreement and writing the best screenplay you're able to write), then that's all you can do.  Attempting to force something to happen, such as make the producer honor his obligation to you in a timely manner, is not one of those things you can do.  I'm not saying you can't always state your position and hold true to it.  But, when it comes to actually making the producer (or anybody, for that matter) do anything, if you think about it, it's impossible.  Now this may be a depressing idea at first.  But if you look into it, you will discover a GEM OF RELIEF:  Because it is impossible to make a producer or anybody do anything, you can now relax.  You no longer have to concern yourself with that impossible task.  You can give turn that over to your Higher Power.

Your lawyer.  

And he can wonder and worry and obsess about forcing the producer to pay you every scintilla of money you have coming to you.

"But what If I don't have a lawyer?" you ask.  Good question.

Get yourself one and fast.  This is a tough business fraught with shysters. 

Actually, I try not to think of show business through such a cynical lens.  I'm of the belief that you will attract a producer who is as honest as you are.  Honest.  Therefore, your real task at hand -- and I don't mean to wax too esoteric here -- is to cultivate your own garden, as Voltaire so aptly put it.  And he did it in French.  So, cultivate your own French garden.  I guess.  Or something like that.  Make sure all your ducks are in a row.  Or, at least, that they're neatly placed in the pond of your French garden that you're cultivating.  I could also talk about mending your own fences, but that additional metaphor would then have you with a fenced-in French garden with a duck pond, which would have you quickly asking the question -- and rightly so --  "What does a fenced-in French garden with a duck pond have to do with screenwriting?!"

Good question.  You got me. 

But you could use it as an opening statement in an arbitration hearing over your screenplay, "One Sunday Too Many" to confuse the producer's attorney.

See?  No need to worry.

DcH