It would be easier if we could see a pic of your fish vs comparing to ours. A male will have a slight amount of "worming" color on its face or lines etc.. where as the female will have a more solid blue depending on stock quality. That is not the only method of sexing just the quickest for me. Your results may vary lol.. Here are a male and female pics of my stock for you.
Keep in mind that young fish may not develop their facial patterns right away. It took almost a year for my males to start showing the worming on their faces. If the fish is small or young, it may be too early to tell.