I got some guppies yesterday and the females look heavily pregnant, but the guy that I brought them from told me that they have about 4 weeks to go and that they can stay in the main tank. I am not so sure because of their size. They are pretty big. Please help me if you can say when they look like they are honing up drop their fry. I really don't want them to have babies in the main tank! PLEASE HELP!