They all look I'm various stages of pregnancy in my experience. The two largest platies look farthest along imo, maybe a few days to a week and a half? The spotted Molly, she looks like mine when she is about 2 weeks from delivery.
When they get boxy and a waddle type, funny way of swimming, and the cloaca starts to protrude or descend a bit, and esp if they become secretive or aggressive all of. Sudden, that's when mine give birth.
My bettas: D'Argo + the girls Jullanar, Lalla, Razz, Rayleigh, Aviendha, Arya, & Lovelylocks
plus the other guys Toni, Eli, and Clinton (platy, guppy, and molly) a kuhli- Burt, 2 yoyos- Duncan and Ma, and otos, Laurel, Hardy, Larry, Curly, and Moe, plus the kitty, Clara the Impossible Girl.
SIP: Turk (teal VT), Azul (royal blue VT), Jerrica Benton (pink cambo CT), Lady Amalthea (blue cambo CT), and Jadzia Dax (blue VT)