So I've had problems with my larger clown being kind of a jerk, knocking over frags, biting my duncan, and chasing my shrimp. Then today I noticed this little bump under him/her and kind of made me wonder if my clown turned into a female. I included a photo to show what I'm talking about.
IME most likely esp if it's the larger of the 2. Clowns can change from male to female but not back or from female to male. Once a female always a female. Watch for biting of an area of rock cleaning it which is a sign of getting ready to spawn plus the female will become gravid. Good luck I think your on your way.