You will want to continue to watch it as it grows. It is feathers are brighter, longer or if you see more skin under the chin it could indicate it is a rooster. Roosters are also a lot more active and put up a fight. They are more noisy and will crow while they are still young.
if you put your index finger on the chick's pubic bone, the finger "fits"in with the indents of the bone, the chick is most likely female. Sexing chicks is usually not done until the chicks are four to six weeks. At that point they start showing signs anyways... just wait, that's the best thing to do. Almost every time we get chickens, we end up getting more roosters than we bargained for, but usually we can find good homes in our area. If it ends up being male, talk to your local humane society, they might be able to help with placing the rooster in a good home.