He's probably a boy but slow developing? But hang out for a bit to determine for sure.
Has he crowed yet?
My Mottled Java roo (who I loved and adored and was the biggest cuddle bug - but I had to rehome because I can't have roos where I live

- that's him on my head in my profile pic! )started crowing at about 9 weeks. And here is a pic of him at 15 weeks. Around the same age as yours I think. You can see how much more developed he is (saddle and sickle feathers, large red comb and wattles) than yours. That's why I say maybe yours is not a guy? Either case, I hope you can keep him. They are lovely!