With female guppies you can tell that she is pregnant when you can see all the babies eyes in the gravid spot, But is this the same with Swords too/all livebreeders? If so i think my female is Prego.
I never go by the color of the fish. Many fish, not all, have some color to their skin so you cannot see a gravid spot. This fish never showed a gravid spot but she dropped over 30 fry just a few hours after I took the picture.
Swordtails often show more gravid spot than that molly does.