I’ve had my platy, Salsa, for about a year now and when I first got it I was 99% sure it was female. It was even from an all female tank. I put her in my tank that had some female guppies and one male. A few months pass and I take a closer look at salsa and it was male. I got her/hI'm at full size so it wasn’t still developing. Is this possible or did both me and the guy at the store make a mistake?