Here is a picture of my female fatties...here is an albino and a het. patternless
..as for signs of ovulation well breeding is one..another is under the belly you will see a white spot start to develop..once you see it you will know..well here are my pictures sorry if they are not the best quality..
they will breed and the female not be ovulating. also you do not look for a while spot. a sign of ovulating is a red spot in the middle of the belly. in the photos you posted is looks like you are showing photos of already gravid females already beginning to form eggs.