It puts on weight teally quick and stays in one cleared area of the aqurium most of the time Parrot fish do not and can not get pregnant. They are egg layers and their eggs are fertilised outside the body.
The fish will appear wider around the stomach. In addition you should be able to see a darkening in color where the stomach starts if the color of the fish is not to dark. In other words, you could not see this on a Black Molly. Still, you will be able to notice that definite belly growth.
A gravid fish looks pregnant. The belly, at least near the time when the eggs will be laid or the fish gives birth (in some species the eggs develop inside the body of the mother), will be markedly-extended. In some live-bearers with translucent bodies (like some guppies, for instance) you'll even be able to see the eyes of the fry (the term for baby fish).
There are, of course, other reasons for a distended belly in a fish -- a full gut, or intestinal parasites, for instance.
You can tell if your fish has a reddish or blackish dot near their but. This is called the gravid spot. And you know when they are about to give birth when their bellies square off or start to look boxy. They could also stay close to the bottom of the tank and not eat for a while.
In some types of fish the female will noticably show the pregnancy with an enlarged belly. Others will begin staying in a certain spot in the tank, especially when it is nearly time while the males will clean out all substrate and "patrol" the parameter keeping any interlopers out of the vicinity.
The vast majority of fish are egg layers so will never get pregnant. The only fish that get pregnant are 'Livebearers'. If you have a male and a female of the same species of livebearer the female will be pregnant anyway. To answer your question. Without you telling me what fish you have I can't know if your fishes are pregnant.
Most fish do not actually become pregnant, but may carry eggs. Livebearers are the exception. If you have a female guppy, platy, molly or swordtail, you can tell she is pregnant because she will swell in the abdomen, and often a dark blotch will appear on the back part of her belly. Right before giving birth, her belly will look square rather than round. A white dot will appear on her genital opening (this is the birthing tube) and she will be antisocial and hide in plants. It's usually best to let her give birth in her usual tank. Some serious breeders will put her in a trap so they can start the fry off on quality fry food straight away, and so that none get eaten (as sometimes the parents or other fish will eat the newborn fry.) A female fish that is not of the species above may swell up in the abdomen when full of eggs. Generally, egglayers are not easy to breed and she probably will not breed in the home aquarium. Very rarely, a female full of eggs can become 'eggbound'. This is life threatening but very uncommon.
Parrotfish are not 'sexually dimorphic', meaning that there are no obvious signs to tell whether one is male or female, without dissecting it.
We used to have some Mollies, and one of them was actually pregnant. She had a puffed out belly on the bottom, different from the others, and because of that her head was more up.
Danios are egg layers and can not get pregnant.
You wouldn't ever be able to tell this, because carp fish do not get pregnant. Pregnancy implies carrying the young internally, which carp do not do.
Goldfish of any type are all egg laying fish which means that they do not get pregnant
With a guppy you need to look at the gravid spot. This is a dark spot in the fish's belly. A large gravid spot indicates the fish is likely to be pregnant. You can tell how pregnant the fish is by how large the spot is. Sorry I have no experience with other species.
Orandas, or any other type of goldfish are egg laying fish, so they do not get pregnant
Your Oscar can not get pregnant. It is an egg layer. It will not be adult or mature until it is around 6 inches long.
Black moors are a variety of goldfish which are egg layers so they can't get pregnant.
A graviid spot is a dark grey spot at the back of the stomach. It is a sign to tell you that your fish is pregnant
The GloFish will have a bloated look and will be fat. If you compare it with the other GloFish , you can usually tell the difference. I'm not sure right now, as my GloFish is also pregnant.
A pregnant fish is called a TWIT
it would not be happy if it does not eat that is normal it will loook desperate that's normal too
Parrot fish do not get pregnant so there is nothing to do.