Hi, I'm new to the world of aquariums. I recently purchased a 20g aquarium, set it up and allowed time to cycle. It has "standard" dimensions, and two out of the water filters, one rated for 40 gallons and another rated for 20 gallons. The tank residents are 7 guppies (5 females and 2 males). Also in the tank are two dwarf gourami's a standard heater, and a bubble wand for great aeration. I do strict water changing schedules (about 10% twice a week.) I also am sure to test water quality(nitrate ph etc. after every change and in addition every other day.) Today I noticed one of my females seems to have "dropped". Though I'm not an expert in this she seems ready to pop. Another one is hovering near the top of the tank by herself, and seems very aggressive to other guppies who swim near her. Is this normal behavior for a pregnant fish? If so, does this mean she is about to give birth? ANY advice/help is greatly appreciated, as I'm new to this and want to do things the RIGHT way.