Ignore that "gravid spot" on your variatus Louise S.
You want to learn to go by shape instead. I would suggest a read through of my thread that I refer to as My Molly's Progress in my signature area. It is full of pictures at various stages of a "pregnancy" and should help you better judge your own platies. I do not see any fish that are close to a drop in your pictures.
I put the pregnancy in quoted because poeciliids do not truly have a pregnancy, they carry developing fry as eggs that get no actual support from their mothers until the fry are big enough to survive outside the fish. Some fish, the goodeids, do have nutritional support provided by the female but poeciliids are not among them.