ok, im new at this. i have guppies and platies in a 20 gallon tank. plenty of hiding places for fry. one of my female platies i believe is pregnant. i see the dark gravid spot and then another more orange-ish spot right beside it. she has lost interest in eating and has isolated herself from the others. is this normal? also one of my male guppies has been showing his mating routine to one of my male platies. now the male platy is isolating himself. what is going on in my tank???