platy Pregnant or no?

If you have a female in with a male chances are she will always be pregnant.

The pregnant platy that is about to give birth (in the next week or so) will be very fat and will have an obvious large black spot on her belly (called the gravid spot). The darker and bigger the spot the closer she is to 'giving birth". The gravid spot is actually the fry inside her showing through.

Just before she's going to give birth she will look even fatter (looks like she'll burst) and usually start hovering in one postion and chasing others away.

It's pretty hard to tell how far along a platy is without pictures. Hope this helps.

When she looks like she'll burst and starts acting strangely put her in the breeding net. I've found they usually have the fry in the morning, so if you think she's getting close put her in at night and check her in the morning. Don't leave her in there for more than 24hrs or she'll stress out, just take her out if she hasn't had them and put her in again in a few days.

Platy fry are fairly big (compared with egglayers) so you can just feed them finely crushed flake.

You should get a 2.5 gallon, and set up an aquairium with dirty water from your next water change into that aquarium. add an airline sponge filter (like dirt cheap, and they wont "eat" fry - like most filters), and drop your pregnant fish inot that. This way they wont stress as much, and the fry will already be in a quaanitein area till they are redy to be sold/returned to your original tank.