The picture doesn't show any black that suggests a gravid spot as far as I can see. Also, all the fins are clamped, so it is hard to be certain if the anal fin has developed or is developing into a gonopodium. The size of the belly may not be conclusive as well fed males.can be quite bulbous.
To the OP, I am concerned by the clamped fins and the tail seems a little patchy. I hope this fish doesn't have a parasite problem. I have seen a lot of platys look like this when they have whitespot or costiasis, etc.