It all depends on it's stage of maturity. If is still young and small it could end up either way but if it is in the six month range and larger, it is almost certain to be a female.
If you have others in the tank to compare with, an undeveloped male will have the anal fin placement slightly forward of where the female location is. The difference is slight enough that without others to compare with most hobbyists are not going to see the difference without experience.
ok i will look. its very shy. when i sit and look at her/him, turns away. i only seen them together once. oreo (the black one) has the P that is noticable and shes younger than the other one. the yellow one i keep questioning. theres times when i see a P and the other times i see full belly size.