Pregnant fish

Question
Hello, I have a 10g tank with 2 dalmatian mollies, 2 platy, 1 black molly, and a sucker fish.
My main problem is 3 of my fish are pregnant and got that way about the same time but I'm not quite sure as to how far apart. Recently all my females have been pooping alot but only one has seemed to try to stay away from the rest. She is off to one corner and her male is by her side. I am wondering if I should go ahead and put her in the plastic breeder? I want to be absolutely positive she is birthing before I put her in there as not to cause her stress on her wait. Is there anything I can do to be sure?
Also, since the other females are not straying from the crowd should I just let them be or should I put them in breeding tanks as well?

Thank you for your time and answer!

Answer
Yes, put them in breeders and please be sure there is salt in the water.  So many people are ill-informed regarding Mollies and freshwater.  People assume that because they survive in it, they are okay in it, but they are not.  In the wild, they are brackish fish.

I suspect females staying to themselves may be ill.  Please get them into a brackish environment, with at least 3 tablespoons of marine salt per gallon.

Good luck.
Renee