We need to give a little insight on the difference of a terminology here. I have seen many post saying, "My fish is pregnant." . Well, this may or may not be true. First of all, egg layers cannot become pregnant. Have you ever heard of a pregnant chicken? I have not. Egglayers, fish that either lay or scatter eggs include cichlids, danios, rasboras, goldfish, tetras, catfish, and anabatids, become gravid. That is they become full of eggs which are laid and fertilized externally.
Livebearers, on the other hand, become pregnant. The eggs are fertilized internally inside of the female by the male. The young are born alive and are free swimming in a short period of time. Fish that can be termed as pregnant include guppies, mollies, swordtails, platys, pike livebearers, and a few others that don't come to mind at this moment.
So, when you post about your fish, you now know the proper terminology.